Online Etymology Dictionary

adenoidal (adj.): 1852, from adenoid (gland) (see adenoid) + -al (1).
adept (adj.): 1690s, "completely skilled" from Latin adeptus "having reached, attained," past participle of adipisci "to come up with, arrive at," figuratively "to attain to, acquire," from ad- "to" (see ad-) + apisci "grasp, attain," related to aptus "fitted" (see apt). Related: Adeptly.
adept (n.): "an expert," especially "one who is skilled in the secrets of anything," 1660s, from Latin adeptus (see adept (adj.)). The Latin adjective was used as a noun in this sense in Medieval Latin among alchemists.
adequate (adj.): 1610s, from Latin adaequatus "equalized," past participle of adaequare "to make equal to," from ad- "to" (see ad-) + aequare "make level," from aequus (see equal (adj.)). The sense is of being "equal to what is required." Related: Adequateness.
adequately (adv.): 1620s, from adequate + -ly (2); originally a term in logic in reference to correspondence of ideas and objects. Meaning "suitably" is recorded from 1680s.
adhere (v.): 1590s, from Middle French adhérer (15c.) or directly from Latin adhaerare "to stick to" (see adherent (adj.)). Originally often of persons, "to cleave to a leader, cause, party, etc." (compare adherent (n.), which still often retains this sense). Related: Adhered; adhering.
adherence (n.): mid-15c., "attachment to a person, support," from Middle French adhérence, from Latin adhaerentia, noun of action from adhaerentem (nominative adhaerens), present participle of adhaerare (see adherent (adj.)).
adherent (adj.): late 14c., from Old French adherent or directly from Latin adhaerentem (nominative adhaerens), present participle of adhaerere "stick to," from ad- "to" (see ad-) + haerere "to stick" (see hesitation).
adherent (n.): "follower, associate, supporter," early 15c., from Old French adherent or directly from Latin adhaerentem (see adherent (adj.)). Meaning "adhesive substance" is from 1912.
adhesion (n.): 1620s, from French adhésion or directly from Latin adhaesionem (nominative adhaesio) "a sticking to," noun of action from past participle stem of adhaerare (see adherent (adj.)).
Adhesion is generally used in the material, and adherence in the metaphysical sense. [Johnson]
adhesive (adj.): 1660s, from French adhésif, formed in French from Latin adhaes-, past participle stem of adhaere (see adherent (adj.)).
adhesive (n.): 1881, from adhesive (adj.). Originally of postage stamps (adhesive stamp is attested from 1840). Of substances that cause to adhere by 1900.
adiabatic (adj.): 1838, from Greek adiabatos "not to be passed through," from a- "not" + dia "through" (see dia-) + batos "passable," from bainein "to go" (see come).
adieu: late 14c., adewe, from French adieu, from phrase a dieu (vous) commant "I commend (you) to God," from a "to" (see ad) + dieu "God," from Latin deum, accusative of deus "god," from PIE *deiwos (see Zeus). Originally said to the party left; farewell was to the party setting forth.
adios: 1837, American English, from Spanish adios, from phrase a dios vos acomiendo "I commend you to God" (see adieu).
adipose (adj.): 1743, from Modern Latin adiposus "fatty," from Latin adipem (nominative adeps, genitive adipis) "soft fat of animals, fat, lard," from Greek aleipha "unguent, fat," related to lipos "grease, fat" (see leave (v.)). Change of -l- to -d- "prob. due to Umbrian influence" [Klein]. But it could as well be a native Italic formation from the same roots, *ad-leip-a "sticking onto."
Adirondack (adj.): 1906, in reference to a type of lawn or deck chair said to have been designed in 1903 by a Thomas Lee, owner of the Westport Mountain Spring, a resort in the Adirondack region of New York State, and commercially manufactured the following year, but said originally to have been called Westport chair after the town where it was first made. Adirondack Mountains is a back-formation from Adirondacks, treated as a plural noun but really from Mohawk (Iroquoian) adiro:daks "tree-eaters," a name applied to neighboring Algonquian tribes, in which the -s is an imperfective affix.
adit (n.): "entrance," c. 1600, from Latin aditus "approach, entrance, a going to or drawing near," from past participle stem of adire "to approach," from ad- "to" (see ad-) + ire "to go," from PIE root *ei- (1) "to go" (see ion).
adjacent (adj.): early 15c., from Latin adiacentem (nominative adiacens) "lying at," present participle of adiacere "lie at, border upon, lie near," from ad- "to" (see ad-) + iacere "to lie, rest," literally "to throw" (see jet (v.)), with notion of "to cast (oneself) down."
adjectival (adj.): 1797, from adjective + -al (1).
adjective: late 14c., as an adjective, "adjectival," in noun adjective, from Old French adjectif (14c.), from Latin adjectivum "that is added to (the noun)," neuter of adjectivus "added," from past participle of adicere "to throw or place (a thing) near," from ad- "to" (see ad-) + comb. form of iacere "to throw" (see jet (v.)). Also as a noun from late 14c. In 19c. Britain, the word itself often was a euphemism for the taboo adjective bloody.
They ... slept until it was cool enough to go out with their 'Towny,' whose vocabulary contained less than six hundred words, and the Adjective. [Kipling, "Soldiers Three," 1888]
adjoin (v.): c. 1300, "unite, ally" from Old French ajoin- stem of ajoindre "join together, unite," from Latin adiungere "fasten on, harness, join to," from ad- "to" (see ad-) + iungere "to bind together" (see jugular). Meaning "be contiguous with, be adjacent to" is from late 14c. Related: Adjoined; adjoining.
adjourn (v.): early 14c., ajournen, "assign a day" (for convening or reconvening), from Old French ajourner (12c.) "meet" (at an appointed time), from the phrase à jorn "to a stated day" (à "to" + journ "day," from Latin diurnus "daily;" see diurnal).

The sense is to set a date for a re-meeting. Meaning "to close a meeting" (with or without intention to reconvene) is from early 15c. Meaning "to go in a body to another place" (1640s) is colloquial. The -d- was added 16c. but is unwarranted, as the compound is not from Latin. Related: Adjourned; adjourning.
adjournment (n.): mid-15c., from Old French ajornement "daybreak, dawn; summons (to appear in court)," from ajorner (see adjourn).
adjudge (v.): late 14c., "to make a judicial decision," from Old French ajugier "to judge, pass judgment on," from Latin adiudicare "grant or award as a judge," from ad- "to" (see ad-) + iudicare "to judge," which is related to iudicem (see judge (v.)). Sense of "have an opinion" is from c. 1400. Related: Adjudged; adjudging.
adjudicate (v.): 1700, from Latin adiudicatus, past participle of adiudicare (see adjudge). Related: Adjudicated; adjudicating.
adjudication (n.): 1690s, from French adjudication or directly from Late Latin adiudicationem (nominative adiudicatio), noun of action from past participle stem of adiudicare (see adjudge).
adjudicative (adj.): 1809; see adjudicate + -ive. Perhaps modeled on French adjudicatif.
adjudicator (n.): 1804, agent noun in Latin form from adjudicate.
adjunct (n.): 1580s, from Latin adiunctus "closely connected, joined, united" (as a noun, "a characteristic, essential attribute"), past participle of adiungere "join to" (see adjoin).
adjunct (adj.): 1590s, from Latin adiunctus "closely connected, joined, united," past participle of adiungere "join to" (see adjoin). Adjunct professor is 1826, American English.
adjuration (n.): late 14c., "exorcism," from Late Latin adjurationem (nominative adjuratio) "a swearing to," noun of action from past participle stem of adjurare (see adjure). Originally a term in exorcism (with conjuration). General sense is from 17c.
adjure (v.): late 14c., "to bind by oath; to question under oath," from Latin adiurare "confirm by oath, add an oath, to swear to in addition," in Late Latin "to put (someone) to an oath," from ad- "to" (see ad-) + iurare "swear," from ius (genitive iuris) "law" (see jurist). Related: Adjured; adjuring.
adjust (v.): late 14c., ajusten, "to correct, remedy;" reborrowed by c. 1600 in sense "arrange, settle, compose," from Middle French adjuster, Old French ajouter "to join" (12c.), from Late Latin adiuxtare "to bring near," from Latin ad- "to" (see ad-) + iuxta "next," related to iungere "to join" (see jugular).

Influenced by folk etymology derivation from Latin iustus "just, equitable, fair." Meaning "to arrange (something) so as to conform with (a standard or another thing)" is from 1660s. Insurance sense is from 1755. Meaning "to get used to" first recorded 1924. Related: Adjusted; adjusting.
adjustable (adj.): 1775, from adjust + -able. Related: Adjustably; adjustability.
adjuster (n.): 1670s, agent noun in English form from adjust. Insurance sense is from 1830.
adjustment (n.): 1640s, from French ajustement or else a native formation from adjust (v.) + -ment.
adjustor (n.): 1857, of certain muscles, agent noun in Latin form from adjust (v.).
adjutant (n.): "military officer who assists superior officers," c. 1600, from Latin adiutantem (nominative adiutans), present participle of adiutare "to give help to, help zealously, serve," frequentative of adiuvare (past participle adiutus) "help, assist, aid, support," from ad- "to" (see ad-) + iuvare "to help, give strength, support," perhaps from same root as iuvenis "young person" (see young).
administer (v.): late 14c., administren, aministren "to manage as a steward," from Old French amenistrer "help, aid, be of service to" (12c., Modern French administrer, the -d- restored 16c.), and directly from Latin administrare "to help, assist; manage, control, guide, superintend; rule, direct," from ad- "to" (see ad-) + ministrare "serve" (see minister (v.)). Used of medicine, etc., "to give," from 1540s. Related: Administered; administering.
administrate (v.): 1630s, from Latin administratus, past participle of administrare (see administer). In modern use a back-formation from administration. Related: Administrated; administrating.
administration (n.): mid-14c., "act of giving or dispensing;" late 14c., "management, act of administering," from Latin administrationem (nominative administratio) "aid, help, cooperation; direction, management," noun of action from past participle stem of administrare (see administer).

Early 15c. as "management of a deceased person's estate." Meaning "the government" is attested from 1731 in British usage. Meaning "a U.S. president's period in office" is first recorded 1796 in writings of George Washington.
administrative (adj.): 1731, from Latin administrativus, from past participle stem of administrare (see administer). Related: Administratively.
administrator (n.): mid-15c., from Middle French administrateur or directly from Latin administrator "a manager, conductor," agent noun from past participle stem of administrare (see administer). Estate sense is earliest. For ending, see -er.
admirable (adj.): mid-15c., "worthy of admiration," from Middle French admirable (Old French amirable), from Latin admirabilis "admirable, wonderful," from admirari "to admire" (see admiration). In early years it also carried a stronger sense of "awe-inspiring."
admirably (adv.): 1590s, from admirable + -ly (2).
admiral (n.): c. 1200, "Saracen commander or chieftain," from Old French amirail (12c.) "Saracen military commander; any military commander," ultimately from medieval Arabic amir "military commander," probably via Medieval Latin use of the word for "Muslim military leader." Meaning "highest-ranking naval officer" in English is from early 15c. The extension of the word's meaning from "commander on land" to "commander at sea" likely began in 12c. Sicily with Medieval Latin amiratus and then spread to the continent, but the word also continued to mean "Muslim military commander" in Europe in the Middle Ages.

The intrusive -d- probably is from influence of Latin ad-mirabilis (see admire). Italian form almiraglio, Spanish almirante are from confusion with Arabic words in al-. As a type of butterfly, from 1720, possibly a corruption of admirable.
admiralty (n.): "naval branch of the English executive," early 15c., admiralte, from Old French amiralte, from amirail (see admiral).
admiration (n.): early 15c., "wonder," from Middle French admiration (14c.) or directly from Latin admirationem (nominative admiratio) "a wondering at, admiration," noun of state from past participle stem of admirari "admire," from ad- "at" (see ad-) + mirari "to wonder," from mirus "wonderful" (see miracle). The sense has weakened steadily since 16c.
admire (v.): early 15c. (implied in admired), from Middle French admirer (Old French amirer, 14c.), or directly from Latin admirari "to wonder at" (see admiration). Related: Admiring; admiringly.