Online Etymology Dictionary

permissible (adj.): early 15c., from Old French permissible (15c.) and directly from Medieval Latin permissibilis, from permiss-, past participle stem of Latin permittere (see permit (v.)).
permission (n.): early 15c., from Latin permissionem (nominative permissio), noun of action from past participle stem of permittere (see permit (v.)).
permissive (adj.): c. 1600, "allowing to pass through," from Old French permissif, from Latin permiss-, past participle stem of permittere "to let go, let pass, let loose" (see permit (v.)). In sense of "tolerant, liberal" it is first recorded 1956; by 1966 it had definite overtones of sexual freedom. Earlier it meant "permitted, allowed" (early 15c.). Related: Permissively; permissiveness.
permit (v.): late 15c., from Middle French permetre and directly from Latin permittere "let pass, let go, let loose; give up, hand over; let, allow, grant, permit," from per- "through" (see per) + mittere "let go, send" (see mission). Related: Permitted; permitting.
permit (n.): "written statement of permission or licence," 1714, from permit (v.).
permutate (v.): 1898 in modern use, "change the order of," from Latin permutatus, past participle of permutare (see permutation). "Probably regarded by those who use it as a back-formation from permutation" [OED]. Related: Permutated; permutating.
permutation (n.): mid-14c., from Old French permutacion "change, shift" (14c.), from Latin permutationem (nominative permutatio) "a change, alteration, revolution," noun of action from past participle stem of permutare "change thoroughly, exchange," from per- "thoroughly" (see per) + mutare "to change" (see mutable).
permute (v.): late 14c., "to change one for another," from French permuter or directly from Latin permutare "to change thoroughly" (see permutation). Mathematical sense from 1878.
pernicious (adj.): early 15c., from Middle French pernicios (13c., Modern French pernicieux) and directly from Latin perniciosus "destructive," from pernicies "destruction, death, ruin," from per- "completely" (see per) + necis "violent death, murder," related to necare "to kill," nocere "to hurt, injure, harm," noxa "harm, injury" (see noxious). Related: Perniciously; perniciousness.
pernickety (adj.): 1808 (pernicktie, in Jamieson), "precise, fastidious," extended form of Scottish pernicky, of uncertain origin, perhaps somehow from particular.
perorate (v.): c. 1600, back-formation from peroration, or else from Latin peroratus, past participle of perorare. Related: Perorated; perorating.
peroration (n.): mid-15c., from Latin perorationem (nominative peroratio) "the ending of a speech or argument of a case," from past participle stem of perorare "argue a case to the end, bring a speech to a close," from per- "to the end" (see per) + orare "to speak, plead" (see orator).
peroxide (n.): 1804, formed in English from per- "large amount" + oxide. Peroxide blonde is attested from 1918.
perp (n.): American English police slang shortening of perpetrator (as in perp walk); by 1940s.
perpendicular (adj.): late 15c., from adverb (late 14c.), from Old French perpendiculer, from Latin perpendicularis "vertical, as a plumb line," from perpendiculum "plumb line," from perpendere "balance carefully," from per- "thoroughly" (see per) + pendere "to weigh, to hang" (see pendant). As a noun from 1570s. Related: Perpendicularly; perpendicularity.
perpensity (n.): "attention," 1704, from Latin perpensus "deliberate," past participle of perpendere "balance carefully" (see perpendicular) + -ity. Noted as obsolete by late 19c.
perpetrate (v.): 1540s, from Latin perpetratus, past participle of perpetrare "to perform, to accomplish," from per- "completely" + patrare "carry out," originally "bring into existence," from pater "father" (see father (n.)). Earlier in English was perpetren, mid-15c., from Old French perpetrer. Neither good nor bad in Latin, first used in English in statutes, hence its sense of "to perform criminally." Related: Perpetrated; perpetrating.
perpetration (n.): mid-15c., from Late Latin perpetrationem (nominative perpetratio) "an accomplishing, performing," noun of action from past participle stem of perpetrare "to perform, accomplish" (see perpetrate).
perpetrator (n.): literally "the one who did it" (in English usually an evil act), 1560s, from Late Latin perpetrator, agent noun of perpetrare "to perform, to accomplish" (see perpetrate). Fem. forms are perpetratress (1811, of Nero's poisoner Locusta); perpetratrix (1862, in reference to Charlotte Corday).
perpetual (adj.): mid-14c., from Old French perpetuel "without end" (12c.) and directly from Latin perpetualis "universal," in Medieval Latin "permanent," from perpetuus "continuous, universal," from perpetis, genitive of Old Latin perpes "lasting," probably from per- "through" + root of petere "to seek, go to, aim at" (see petition (n.)). Related: Perpetually. Perpetual motion is attested from 1590s.
perpetuate (v.): 1520s, a back-formation from perpetuation or else from Latin perpetuatus, past participle of perpetuare "to make perpetual," from perpetuus (see perpetual). Related: Perpetuated; Perpetuating.
perpetuation (n.): late 14c., from Medieval Latin perpetuationem (nominative perpetuatio), noun of action from past participle stem of perpetuare (see perpetuate).
perpetuity (n.): late 14c., from Old French perpetuité "permanence, duration" (13c., Modern French perpétuité) and directly from Latin perpetuitatem (nominative perpetuitas) "uninterrupted duration, continuity, continuous succession," from perpetuus (see perpetual).
perpetuous (adj.): "perpetual," 1610s, from Latin perpetuus "continuous, unbroken, uninterrupted" (see perpetual).
perplex (v.): late 14c. as an adjective, "perplexed, puzzled, bewildered," from Latin perplexus "involved, confused, intricate;" but Latin had no corresponding verb *perplectere. The Latin compound would be per "through" (see per) + plexus "entangled," past participle of plectere "to twine, braid, fold" (see complex (adj.)).

The form of the English adjective shifted to perplexed by late 15c., probably to conform to other past participle adjectives. The verb is latest attested of the group, in 1590s, evidently a back-formation from the adjective. Related: Perplexing, which well describes the history of the word.
perplexed (adj.): late 15c., past participle adjective; see perplex. A case of a past participle form attested centuries before the verb (perplex isn't recorded until 17c.). Related: Perplexedly; perplexedness.
perplexity (n.): c. 1300, "bewilderment," from Old French perplexite "confusion, perplexity," from Late Latin perplexitatem (nominative perplexitas), from Latin perplexus "confused, involved, interwoven," from per- "completely" + plexus "entangled," past participle of plectere "to twine" (see complex (adj.)). From 1590s as "something that causes perplexity."
perquisite (n.): mid-15c., "property acquired other than by inheritance," from Medieval Latin perquisitum "thing gained, profit," in classical Latin, "thing sought after," noun use of neuter past participle of perquirere "to seek, ask for," from per- "thoroughly" (see per) + quærere "to seek" (see query (v.)). For Latin vowel change, see acquisition. General meaning "fee or profit on top of regular wages" first recorded 1560s.
Perrier: proprietary name of a natural mineral water from southern France, first attested in English 1904.
Perry: surname attested from late 12c., literally "dweller by the pear tree."
perse (adj.): late 14c., "blue, bluish-gray," later "purplish-black," from Old French pers "(dark) blue, livid; wan, pale," from Late Latin persus, perhaps a back-formation from one of the early European forms of Persia.
persea (n.): sacred fruit-bearing tree of Egypt and Persia, c. 1600, from Latin persea, from Greek persea. Used from early 19c. of a genus of trees and shrubs in the West Indies.
persecute (v.): mid-15c., "to oppress for the holding of a belief or opinion," from Middle French persécuter "pursue, torment, open legal action" (14c.), from Latin persecutus, past participle of persequi "to pursue" (see persecution). Related: Persecuted; persecuting.
persecution (n.): mid-14c., "oppression for the holding of a belief or opinion," from Old French persecucion "persecution, damage, affliction, suffering" (12c.) and directly from Latin persecutionem (nominative persecutio), noun of action from past participle stem of persequi "follow, pursue, hunt down; proceed against, prosecute, start a legal action," from per- "through" (see per) + sequi "follow" (see sequel). Psychological persecution complex is recorded from 1961; earlier persecution mania (1892).
persecutor (n.): early 15c., from Anglo-French persecutour, Old French persecutor "persecutor, enemy" (12c., Modern French persécuteur), from Latin persecutor, agent noun from persequi (see persecution).
Perseid (n.): meteor from an annual shower that appears to radiate from the constellation Perseus, 1867, from Modern Latin Perseides (plural), from Greek Perseis "daughter of Perseus" (see Perseus; also see -id). The name might have been introduced in English via the writings of Italian astronomer Giovanni Schiaparelli. Other recorded old names for them in English include August meteors and Tears of St. Lawrence.
Persephone: wife of Hades, queen of the netherworld, identified with Kore, daughter of Zeus and Demeter, from Greek Persephone (see person).
Persepolis: ancient capital of Persia, founded 6c. B.C.E. by Darius the Great; from Greek, literally "city of the Persians," from Perses "Persians" (see Persian) + -polis "city" (see polis). The modern Iranian name for the place is Takht-e-jamshid, literally "throne of Jamshid," a legendary king whose name was substituted when Darius was forgotten.
Perseus: son of Zeus and Danaë, slayer of Medusa, from Greek Perseus, of unknown origin.
perseverance (n.): mid-14c., from Old French perseverance "persistence, endurance" (12c., Modern French persévérance) and directly from Latin perseverantia "steadfastness, constancy," from perseverantem (nominative perseverans), from perseverare (see persevere).
perseverant (adj.): mid-14c. (implied in perseverantly), from Middle French persévérant (12c.), present participle of persévérer (see persevere).
perseverate (v.): 1915, in psychology, a back-formation from perseveration. Related: Perseverating; perseverative.
perseveration (n.): early 15c., "duration, quality of persisting; will to persevere," from Old French perseveracion "persistence, stubbornness" (13c.) and directly, from Latin perseverationem (nominative perseveratio), noun of action from past participle stem of perseverare (see persevere). Psychological sense (1915) is from German.
persevere (v.): mid-14c., from Old French perseverer "continue, persevere, endure" and directly from Latin perseverare "continue steadfastly, persist," from persevereus "very strict, earnest," from per- "very" (see per) + severus "strict" (see severity). Related: Persevered; persevering.
Persia: from Latin Persia "Persia," from Greek Persis, from Old Persian Parsa (cognate with Persian Fars, Hebrew Paras, Arabic Faris).
Persian: c. 1400, percynne (adj.), Old English Perse (n.), both from Latin *Persianus (the adjective via Old French persien), from Persia "Persia" (see Persia). First record of Persian cat is from 1785.
persiflage (n.): 1757, from French persiflage, from persifler "to banter" (18c.), from Latin per- "through" (see per) + French siffler "to whistle, hiss," from collateral form of Latin sibilare "to hiss," possibly of imitative origin. Said to have been introduced in English by Chesterfield.
persimmon (n.): 1610s, from Powhatan (Algonquian) pasimenan "fruit dried artificially," from pasimeneu "he dries fruit," containing proto-Algonquian */-min-/ "fruit, berry."
Persis: fem. proper name, from Latin, from Greek Persis, literally "a Persian woman," related to Perses "Persian" (see Persian).
persist (v.): 1530s, from Middle French persister (14c.), from Latin persistere "abide, continue steadfastly," from per- "thoroughly" (see per) + sistere "come to stand, cause to stand still" (see assist (v.)). Related: Persisted; persisting.