Online Etymology Dictionary

amorous (adj.): c. 1300, from Old French amorous (Modern French amoureux), from Late Latin amorosum, from amor "love," from amare "to love" (see Amy). Related: Amorously; amorousness.
Eros (n.): god of love, late 14c., from Greek eros (plural erotes), "god or personification of love," literally "love," from eran "to love," erasthai "to love, desire," which is of uncertain origin.

Freudian sense of "urge to self-preservation and sexual pleasure" is from 1922. Ancient Greek distinguished four ways of love: erao "to be in love with, to desire passionately or sexually;" phileo "have affection for;" agapao "have regard for, be contented with;" and stergo, used especially of the love of parents and children or a ruler and his subjects.
inamorato (n.): "male lover; man who is in love," 1590s, from Italian innamorato, noun use of masc. past participle of innamorare "to fall in love" (see inamorata).
agape (n.): c. 1600, from Greek agape "brotherly love, charity," from agapan "greet with affection, love," which is of unknown origin. Agape was used by early Christians for their "love feast" held in connection with the Lord's Supper. In modern use, often in simpler sense of "Christian love" (1856, frequently opposed to eros as "carnal or sensual love").
philology (n.): late 14c., "love of learning," from Latin philologia "love of learning, love of letters, love of study, literary culture," from Greek philologia "love of discussion, learning, and literature; studiousness," from philo- "loving" (see philo-) + logos "word, speech" (see logos).

Meaning "science of language" is first attested 1716 (philologue "linguist" is from 1590s; philologer "linguistic scholar" is from 1650s); this confusing secondary sense has not been popular in the U.S., where linguistics is preferred. Related: Philological.
inamorata (n.): "female lover, woman with whom one is in love," 1650s, from Italian innamorata "mistress, sweetheart," noun use of fem. of innamorato, past participle of innamorare "to fall in love," from in "in" (from Latin, see in) + amore "love," from Latin amor (see Amy).
Erato: muse who presided over lyric poetry, literally "the Lovely," from Greek erastos "loved, beloved; lovely, charming," verbal adjective of eran "to love, to be in love with" (see Eros).
Cupid: Roman god of passionate love, late 14c., from Latin Cupido, personification of cupido "desire, love," from cupere "to desire" (see cupidity). Identified with Greek Eros. Cupid's bow as a shape, especially of lips, is from 1858.
enamor (v.): c. 1300, from Old French enamorer "to fall in love with; to inspire love" (12c., Modern French enamourer), from en- "in, into" (see en- (1)) + amor "love," from amare "to love" (see Amy). Since earliest appearance in English, it has been used chiefly in the past participle (enamored) and with of or with. An equivalent formation to Provençal, Spanish, Portuguese enamorar, Italian innamorare.
Ishtar: ancient Sumero-Babylonian goddess of love and fertility, counterpart of Phoenician Astarte (q.v.), from Akkadian Ishtar.
unrequited (adj.): 1540s, from un- (1) "not" + past participle of requite (v.). The earliest reference is to love.
unlovely (adj.): late 14c., "not evoking feelings of love," from un- (1) "not" + lovely. Meaning "ugly" is recorded from 1390s.
endearment (n.): "act of endearing," 1610s, from endear + -ment. Meaning "obligation of gratitude" is from 1620s; that of "action expressive of love" is from 1702.
coup de foudre (n.): 1779, from French coup de foudre, literally "stroke of lightning," also "love at first sight" (see coup).
hickey (n.): "any small gadget," 1909, American English, of unknown origin. For the "love-bite" sense, see hickie.
Erastus: masc. proper name, Latin, literally "beloved," from Greek erastos, verbal adjective of eran "to love" (see Eros).
erotomaniac (n.): "one driven mad by passionate love" (sometimes also used in the sense of "nymphomaniac"), 1858, from erotomania.
philtrum (n.): dimple in the middle of the upper lip, 1703, medical Latin, from Greek philtron, literally "love charm" (see philtre).
fancy-free (adj.): "free from the trammels of love, having the 'fancy' or affection free," 1580s, from fancy (n.) + free (adj.).
erotomania (n.): 1813, defined then as "Desperate love; sentimentalism producing morbid feelings," from comb. form of erotic + mania.
languishment (n.): 1540s, "sorrow caused by love;" 1590s, "sickness; m,ental distress," from languish (v.) + -ment.
amour (n.): c. 1300, "love," from Old French amour, from Latin amorem (nominative amor) "love, affection, strong friendly feeling" (it could be used of sons or brothers, but especially of sexual love), from amare "to love" (see Amy). The accent shifted 15c.-17c. to the first syllable as the word became nativized, then shifted back as the naughty or intriguing sense became primary and the word was felt to be a euphemism.
A common ME word for love, later accented ámour (cf. enamour). Now with suggestion of intrigue and treated as a F[rench] word. [Weekley]
Kama Sutra (n.): also Kamasutra, 1871, from Sanskrit Kama Sutra, name of the ancient treatise on love and sexual performance, from kama "love, desire," from PIE *ka-mo-, suffixed form of root *ka- "to like, desire" (see whore (n.)) + sutra "series of aphorisms" (see sutra).
venereal (adj.): early 15c., "of or pertaining to sexual desire or intercourse," from Latin venereus, venerius "of Venus; of sexual love," from venus (genitive veneris) "sexual love, sexual desire" (see Venus). Used of sexually transmitted diseases from 1650s. Related: Venereally.
pederasty (n.): "sodomy of a man with a boy," c. 1600, from French pédérastie or directly from Modern Latin pæderastia, from Greek paiderastia "love of boys," from paiderastes "pederast, lover of boys," from pais (genitive paidos) "child, boy" (see pedo-) + erastes "lover," from erasthai "to love" (see Eros).
heart (v.): Old English hiertan "give heart to," from heart (n.). Shakespeare used it as "take to heart" (c. 1600); 1866 of cabbages, "to form a heart." Meaning "to love" is by 1993, from the popular New York state tourism campaign that used the heart symbol in place of the word "love."
aloha: 1798, Hawaiian aloha, Maori aroha, an expression used in greeting or valediction, literally "love, affection, pity." Sometimes aloha 'oe, from 'oe "to you."
amicus curiae: 1610s, Latin, literally "friend of the court;" plural is amici curiae. From Latin amicus "friend," related to amare "to love" (see Amy) + curia "court" (see curia).
Philemon: masc. proper name, in Greek mythology a pious man, husband of Baucis; from Greek philemon, literally "loving, affectionate," from philein "to love" (see philo-).
amable (adj.): "friendly, courteous," early 15c., from Old French amable, from Latin amabilem "lovely," from amare "to love" (see Amy). Related: Amably; amability.
gypsophila (n.): genus of the pink family, 1771, from Modern Latin (Linnaeus), from Greek gypsos "chalk, gypsum" (see gypsum) + philein "to love" (see philo-).
smitten (adj.): mid-13c., "struck hard, afflicted, visited with disaster," past participle adjective from smite. Sense of "inspired with love" is from 1660s.
nutty (adj.): early 15c., "nut-like," from nut + -y (2). Meaning "crazy" is from 1898 (see nuts); earlier "amorous, in love (with)," 1821. Related: Nuttiness.
Erasmus: masc. proper name, Latin, literally "beloved;" related to Greek erasmios "lovely, pleasant," from eran "to love" (see Eros). Related: Erasmian.
paramour (n.): c. 1300, noun use of adverbial phrase par amour (c. 1300) "passionately, with strong love or desire," from Anglo-French and Old French par amour, from accusative of amor "love," from amare "to love" (see Amy). Originally a term for Christ (by women) or the Virgin Mary (by men), it came to mean "darling, sweetheart" (mid-14c.) and "mistress, concubine, clandestine lover" (late 14c.).
free (v.): Old English freogan "to free, liberate, manumit," also "to love, think of lovingly, honor;" also "to rid (of something)," from freo "not in bondage" (see free (adj.)). The forking sense in the Germanic adjective is reflected in the verbs that grew from it in the daughter languages. Compare Old Frisian fria "to make free;" Old Saxon friohan "to court, woo;" German befreien "to free," freien "to woo;" Old Norse frja "to love;" Gothic frijon "to love." Related: Freed; freeing.
charity (n.): mid-12c., "benevolence for the poor," from Old French charité "(Christian) charity, mercy, compassion; alms; charitable foundation" (12c., Old North French carité), from Latin caritatem (nominative caritas) "costliness, esteem, affection" (in Vulgate often used as translation of Greek agape "love" -- especially Christian love of fellow man -- perhaps to avoid the sexual suggestion of Latin amor), from carus "dear, valued," from PIE *karo-, from root *ka- "to like, desire" (see whore (n.)).

Vulgate also sometimes translated agape by Latin dilectio, noun of action from diligere "to esteem highly, to love" (see diligence).
Wyclif and the Rhemish version regularly rendered the Vulgate dilectio by 'love,' caritas by 'charity.' But the 16th c. Eng. versions from Tindale to 1611, while rendering agape sometimes 'love,' sometimes 'charity,' did not follow the dilectio and caritas of the Vulgate, but used 'love' more often (about 86 times), confining 'charity' to 26 passages in the Pauline and certain of the Catholic Epistles (not in I John), and the Apocalypse .... In the Revised Version 1881, 'love' has been substituted in all these instances, so that it now stands as the uniform rendering of agape. [OED]
Sense of "charitable foundation or institution" in English attested by 1690s.
Freya: goddess of sexual love and beauty in Norse mythology, from Old Norse Freyja, which is related to Old English frea "lord;" Old Saxon frua, Middle Dutch vrouwe "woman, wife," German Frau; see frau).
Frigga is usually considered the goddess of married love; Freya, the goddess of love, the northern Venus. Actually, Frigga is of the Aesir family of Scandinavian myth; Freya, of the Vanir family; the two lines of belief merged, and the two goddesses are sometimes fused, and sometimes confused. [Joseph T. Shipley, "The Origins of English Words," 1984]
veneration (n.): early 15c., from Old French veneracion, from Latin venerationem (nominative veneratio) "reverence, profoundest respect," noun of action from past participle stem of venerari "to worship, revere," from venus (genitive veneris) "beauty, love, desire" (see Venus).
venial (adj.): c. 1300, "pardonable," from Old French venial "pardonable, excusable" (13c.) and directly from Late Latin venialis "pardonable," from Latin venia "forgiveness, indulgence, pardon," related to venus "sexual love, desire" (see Venus). Related: Venially.
Hathor: cow-goddess of love and joy in ancient Egypt, identified by the Greeks with their Aphrodite, from Greek Hathor, from Egyptian Het-Heru "mansion of Horus," or possibly Het-Herh "the house above."
billet-doux (n.): also billet doux, 1670s, "love letter," French, literally "sweet note," from billet "document, note" (14c., diminutive of bille; see bill (n.1)) + doux "sweet," from Latin dulcis (see dulcet).
Amanda: fem. proper name, literally "worthy to be loved," fem. of Latin amandus "pleasing," gerundive of amare "to love" (see Amy). A top 10 list name for girls born in U.S. between 1976 and 1995.
amenity (n.): late 14c., "quality of being pleasant or agreeable," from Old French amenite, from Latin amoenitatem (nominative amoenitas) "delightfulness, pleasantness," from amoenus "pleasant," perhaps related to amare "to love" (see Amy).
amicable (adj.): early 15c., from Late Latin amicabilis "friendly," a word in Roman law, from Latin amicus "friend," related to amare "to love" (see Amy). Also see amiable.
amigo (n.): "friend, comrade," often a form of address, 1837, American English (first attested in the phrase adios, Amigo), from Spanish amigo, literally "friend," from Latin amicus "friend," related to amare "to love" (see Amy).
amity (n.): mid-15c., "friendly relations," from Old French amitie (13c.); earlier amistie (11c.), from Vulgar Latin *amicitatem (nominative *amicitas) "friendship," corresponding to Latin amicitia, from amicus (adj.) "friendly;" related to amare "to love" (see Amy).
aphrodisiac (n.): 1719, from Greek aphrodisiakos "inducing sexual desire," from aphrodisios, "pertaining to Aphrodite; sexual pleasure; a temple of Aphrodite," Greek goddess of love and beauty. As an adjective from 1830 (earlier was aphrodisical, 1719)
predilection (n.): 1742, from French prédilection (16c.), noun of action from Medieval Latin praedilectus, past participle of prediligere "prefer before others," from Latin prae- "before" (see pre-) + diligere "choose, love" (see diligent).
sybarite (n.): "person devoted to pleasure," 1590s, literally "inhabitant of Sybaris," ancient Greek town in southern Italy, whose people were noted for their love of luxury. From Latin Sybarita, from Greek Sybarites.