Online Etymology Dictionary

accelerator (n.): 1610s, from Latin accelerator, agent noun from accelerare (see accelerate). Motor vehicle sense is from 1900.
accent (n.): late 14c., "particular mode of pronunciation," from Middle French accent, from Old French acent (13c.), from Latin accentus "song added to speech," from ad- "to" (see ad-) + cantus "a singing," past participle of canere "to sing" (see chant (v.)). Loan-translation of Greek prosoidia, from pros- "to" + oide "song," which apparently described the pitch scheme in Greek verse. The decorating sense of "something that emphasizes or highlights" is from 1972.
accent (v.): "to pronounce with accent or stress," 1520s, from Middle French accenter, from Old French acenter, from accent (see accent (n.)). Related: Accented; accenting.
accentuate (v.): 1731, from Medieval Latin accentuatus, past participle of accentuare "to accent," from Latin accentus (see accent (n.)). Originally "to pronounce with an accent;" meaning "emphasize" is recorded from 1865.
You've got to accentuate the positive
Eliminate the negative
Latch on to the affirmative
Don't mess with Mister In-Between

["Ac-Cent-Tchu-Ate the Positive," 1944, music by Harold Arlen, lyrics by Johnny Mercer]
Related: Accentuated; accentuating.
accentuation (n.): 1690s, from Medieval Latin accentuationem (nominative accentuatio) "intoning, chanting," noun of action from past participle stem of accentuare (see accentuate).
accept (v.): late 14c., "to take what is offered," from Old French accepter (14c.) or directly from Latin acceptare "take or receive willingly," frequentative of accipere "receive," from ad- "to" (see ad-) + capere "to take" (see capable). Related: Accepted; accepting.
acceptability (n.): 1660s, from Late Latin acceptabilitas, from Latin acceptabilis (see acceptable).
acceptable (adj.): late 14c., from Old French acceptable, from Latin acceptabilis "worthy of acceptance," from acceptare (see accept). Related: Acceptably.
acceptance (n.): 1570s, from Middle French acceptance, from accepter (see accept). Earlier in same sense was acceptation (late 14c.).
access (n.): early 14c., "an attack of fever," from Old French acces "onslaught, attack; onset (of an illness)" (14c.), from Latin accessus "a coming to, an approach," noun use of past participle of accedere "approach" (see accede). The later senses are directly from Latin. Meaning "an entrance" is from c.1600. Meaning "habit or power of getting into the presence of (someone or something)" is from late 14c.
access (v.): 1962, originally in computing, from access (n.). Related: Accessed; accessing.
accessibility (n.): c.1800, from accessible + -ity.
accessible (adj.): c.1400, "affording access," from Middle French accessible, from Late Latin accessibilis, verbal adjective from Latin accessus "a coming near, approach" (see access (n.)). Meaning "easy to reach" is from 1640s; Of art or writing, "able to be readily understood," 1961 (a term not needed in the years before writing or art often deliberately was made not so).
accession (n.): "act of coming to a position," especially of a throne, 1640s, from Latin accessionem (nominative accessio) "a going to, joining, increase," noun of action from past participle stem of accedere (see accede).
accessorize (v.): 1939, from accessory + -ize. Related: Accessorized; accessorizing.
accessory (n.): also accessary, early 15c. as a legal term in the criminal sense of "one aiding in a crime;" also "that which is subordinate to something else," from Late Latin accessorius, from accessor, agent noun from accedere (see access (n.)). Attested from 1896 as "woman's smaller articles of dress," hence accessorize.
accessory (adj.): 1550s, "subordinate," from Late Latin accessorius, from accessor, agent noun from accedere (see access (n.)). Meaning "aiding in crime" is from c.1600.
accidence (n.): late 14c., in philosophy, "non-essential or incidental characteristic," also "part of grammar dealing with inflection" (mid-15c.), in some cases a misspelling of accidents, or else directly from Latin accidentia (used as a term in grammar by Quintilian), neuter plural of accidens, present participle of accidere (see accident). The grammar sense is because they change in accordance with use.
accident (n.): late 14c., "an occurrence, incident, event," from Old French accident (12c.), from Latin accidentem (nominative accidens), present participle of accidere "happen, fall out, fall upon," from ad- "to" (see ad-) + cadere "fall" (see case (n.1)). Meaning grew from "something that happens, an event," to "something that happens by chance," then "mishap." Philosophical sense "non-essential characteristic of a thing" is late 14c. Meaning "unplanned child" is attested by 1932.
accidental (adj.): late 14c., "non-essential," from Old French accidentel or directly from Medieval Latin accidentalis, from Latin accidentem (see accident). Meaning "outside the normal course of nature" is from early 15c.; that of "coming by chance" is from 1570s.
accidental (n.): late 14c., "non-essential quality," from accidental (adj.). The musical sense is from 1868.
accidentally (adv.): late 14c., "non-essentially," also "unnaturally," from accidental + -ly (2). Meaning "unintentionally" is recorded from 1580s; phrase accidentally on purpose is recorded from 1862.
acclaim (n.): "act of acclaiming," 1667 (in Milton), from acclaim (v.).
acclaim (v.): early 14c., "to lay claim to," from Latin acclamare "to cry out at" (see acclamation); the meaning "to applaud" is recorded by 1630s. Related: Acclaimed; acclaiming.
acclamation (n.): 1540s, from Latin acclamationem (nominative acclamatio) "a calling, exclamation, shout of approval," noun of action from past participle stem of acclamare "shout approval or disapproval of, cry out at," from ad- "toward" (see ad-) + clamare "cry out" (see claim (v.)). As a method of voting en masse, by 1801, probably from the French Revolution.
acclimate (v.): 1792, from French acclimater, from à "to" (see ad-) + climat (see climate). Related: Acclimated; acclimating. The extended form acclimatize is now more common.
acclimation (n.): 1826, noun of action from acclimate.
acclimatize (v.): 1836; see acclimate + -ize; a more recent formation than acclimate and replacing it in many uses. Related: Acclimatized; acclimatizing.
acclivity (n.): 1610s, from Latin acclivitatem (nominative acclivitas) "an ascending direction, an upward steepness," from acclivis "mounting upwards, ascending," from ad- "up" (see ad-) + clivus "hill, a slope," from PIE *klei-wo-, suffixed form of *klei- "to lean" (see lean (v.)).
accolade (n.): 1620s, from French accolade (16c.), from Provençal acolada or Italian accollata, ultimately from noun use of a fem. past participle from Vulgar Latin *accollare "to embrace around the neck," from Latin ad- "to" (see ad-) + collum "neck" (see collar).

The original sense is of an embrace about the neck or the tapping of a sword on the shoulders to confer knighthood. Extended meaning "praise, award" is from 1852. Also see -ade. Earlier was accoll (mid-14c.), from Old French acolee "an embrace, kiss, especially that given to a new-made knight," from verb acoler. The French noun in the 16c. was transformed to accolade, with the foreign suffix.
accommodate (v.): 1530s, from Latin accomodatus "suitable," past participle of accomodare "make fit, adapt, fit one thing to another," from ad- "to" (see ad-) + commodare "make fit," from commodus "fit" (see commode). Related: Accommodated; accommodating.
accommodating (adj.): "obliging," 1775, present participle adjective from accommodate.
accommodation (n.): "room and provisions, lodging," c.1600, now usually plural (accommodations) and chiefly U.S.; from French accommodation, from Latin accommodationem (nominative accommodatio), noun of action from past participle stem of accommodare (see accommodate). Meaning "appliance, anything which affords aid" is from 1610s; that of "act of accommodating" is from 1640s.
accommodations (n.): "lodgings and entertainment," see accommodation.
accompaniment (n.): 1744, from French accompagnement (13c.), from accompagner (see accompany). Musical sense is earliest.
accompanist (n.): "performer who takes the accompanying part in music," 1833, from accompany + -ist. Fowler prefers accompanyist.
accompany (v.): early 15c., "to be in company with," from Middle French accompagner, from Old French acompaignier (12c.) "take as a companion," from à "to" (see ad-) + compaignier, from compaign (see companion). Related: Accompanied; accompanying.
accomplice (n.): 1580s (earlier complice, late 15c.), from Old French complice "a confederate," from Late Latin complicem (nominative complex) "partner, confederate," from Latin complicare "fold together" (see complicate). With parasitic a- on model of accomplish, etc., or perhaps by assimilation of indefinite article in phrase a complice.
accomplish (v.): late 14c., from Old French acompliss-, present participle stem of acomplir "to fulfill, fill up, complete" (12c.), from Vulgar Latin *accomplere, from Latin ad- "to" (see ad-) + complere "fill up" (see complete (adj.)). Related: Accomplished; accomplishing.
accomplished (adj.): late 15c., "perfect as a result of training," past participle adjective from accomplish (q.v.). Meaning "completed" is from 1570s.
accomplishment (n.): early 15c., "performance of a task; state of completion," from Old French acomplissement "action of accomplishing," from acomplir (see accomplish). Meaning "thing completed" and that of "something that completes" someone and fits him or her for society are from c.1600.
accord (v.): early 12c., from Old French acorder (12c.) "reconcile, agree, be in harmony," from Vulgar Latin *accordare "make agree," literally "be of one heart, bring heart to heart," from Latin ad- "to" + cor (genitive cordis) "heart" (see heart). Related: Accorded; according.
accord (n.): late 13c., accourd, from Old French acord "agreement," a back-formation from acorder (see accord (v.)).
accordance (n.): c.1300, "compliance;" early 14c., "agreement, concurrence," from Old French acordance "agreeing, reconciliation, harmony," noun of action from acorder (see accord). Of things, "conformity, compatibility, harmony," late 14c. Phrase in accordance with is attested from c.1810 (in Middle English, in accordance of was the usual form).
according: c.1300, "matching, similar, correponding," present participle adjective and adverb from accord (v.). Meanings "conforming (to), compliant, in agreement; consistent, harmonious; suitable, appropriate" are from late 14c. According to "referring to," literally "in a manner agreeing with" is attested from mid-15c.
accordingly (adv.): mid-14c., "in agreement with," from according + -ly (2). From mid-15c. as "properly; adequately;" meaning "in agreement with logic or expectation" is recorded 1680s.
accordion (n.): 1831, from German Akkordion, from Akkord "musical chord, concord of sounds, be in tune" (cf. Italian accordare "to attune an instrument"); ultimately from same source as English accord (v.), with suffix on analogy of clarion, etc. Invented 1829 by piano-maker Cyrill Demian (1772-1847) of Vienna.
accost (v.): 1570s, from Middle French accoster "move up to," from Italian accostare or directly from Late Latin accostare "come up to the side," from Latin ad- "to" (see ad-) + costa "rib, side" (see coast (n.)). The original notion is of fleets of warships attacking an enemy's coast. Related: Accosted; accosting.
accouchement (n.): 1803, from French accouchement, noun of action from accoucher (see accoucheur).
accoucheur (n.): 1759, "midwife" (properly, "male midwife"), from French accoucheur (Jules Clément, later 17c.), agent noun from accoucher "to go to childbed, be delivered" (13c.) originally simply "to lie down" (12c.), from Old French culcher "to lie," from Latin collocare, from com- "with" (see com-) + locare "to place" (see locate). The fem. is accoucheuse (1847).