Online Etymology Dictionary

receptor (n.): mid-15c., from Old French receptour or directly from Latin receptor, agent noun from recipere (see receive). Medical use from 1900.
recess (n.): 1530s, "act of receding," from Latin recessus "a going back, retreat," from recessum, past participle of recedere "to recede" (see recede). Meaning "hidden or remote part" first recorded 1610s; that of "period of stopping from usual work" is from 1620s, probably from parliamentary notion of "recessing" into private chambers.
recess (v.): 1809, from recess (n.). Related: Recessed; recessing.
recession (n.): 1640s, "act of receding, a going back," from French récession "a going backward, a withdrawing," and directly from Latin recessionem (nominative recessio) "a going back," noun of action from past participle stem of recedere (see recede).

Sense of "temporary decline in economic activity," 1929, noun of action from recess (q.v.):
The material prosperity of the United States is too firmly based, in our opinion, for a revival in industrial activity -- even if we have to face an immediate recession of some magnitude -- to be long delayed. ["Economist," Nov. 2, 1929]
Ayto notes, "There was more than a hint of euphemism in the coining of this term."
recessional (adj.): 1858, from recession + -al (1). As a noun, "hymn sung while the clergy and choir are leaving church," 1864, with -al (2).
recessive (adj.): 1670s, from Latin recess-, past participle stem of recedere (see recede) + -ive. Linguistics sense is from 1879; in genetics, 1900, from German recessiv (Mendel, 1865). Related: Recessiveness.
recharge (v.): early 15c., "to reload" (a vessel), from re- "again, back" + charge "to load" (q.v.); modeled on Old French rechargier "to load, load back on" (13c.). Meaning "re-power a battery" is from 1876. Related: Recharged; recharging. The noun is recorded from 1610s in English.
rechargeable (adj.): 1901 of batteries, etc., from recharge + -able. Earlier in financial accounts.
recherche (adj.): 1722, from French recherché "carefully sought out," past participle of rechercher "to seek out" (12c.), from re-, here perhaps suggesting repeated activity (see re-) + chercher "to search," from Latin circare, in Late Latin "to wander hither and thither," from circus "circle" (see circus). Commonly used 19c. of food, styles, etc., to denote obscure excellence.
recidivate (v.): "fall back; relapse," 1520s, from Medieval Latin recidivatus, past participle of recidivare "to relapse" (see recidivist). Related: Recidivated; recidivating.
recidivism (n.): "habit of relapsing" (into crime), 1882, from recidivist + -ism, modeled on French récidivisme, from récidiver.
recidivist (n.): "relapsed criminal," 1863, from French récidiviste, from récidiver "to fall back, relapse," from Medieval Latin recidivare "to relapse into sin," from Latin recidivus "falling back," from recidere "fall back," from re- "back, again" (see re-) + comb. form of caedere "to fall" (see -cide). Recidivation in the spiritual sense is attested from early 15c., was very common 17c.
recipe (n.): 1580s, "medical prescription," from Middle French récipé (15c.), from Latin recipe "take!," second person imperative singular of recipere "to take" (see receive); word written by physicians at the head of prescriptions. Figurative use from 1640s. Meaning "instructions for preparing food" first recorded 1743. The original sense survives only in the pharmacist's abbreviation Rx.
recipient (n.): 1550s, from Middle French récipient (16c.) and directly from Latin recipientem (nominative recipiens), present participle of recipere (see receive). As an adjective from 1610s. Related: Recipience; recipiency.
reciprocal (adj.): 1560s, with -al (1) + stem of Latin reciprocus "returning the same way, alternating," from pre-Latin *reco-proco-, from *recus (from re- "back;" see re-, + -cus, adjective formation) + *procus (from pro- "forward;" see pro-, + -cus. Related: Reciprocally. The noun meaning "that which is reciprocal" (to another) is from 1560s.
reciprocate (v.): "to return, requite," 1610s, back-formation from reciprocation, or else from Latin reciprocatus, past participle of reciprocare "rise and fall, move back and forth; reverse the motion of," from reciprocus (see reciprocal). Related: Reciprocated; reciprocating.
reciprocating (adj.): "moving back and forth," 1690s, present participle adjective from reciprocate (v.). Specifically of machines by 1822.
reciprocation (n.): 1520s, "mode of expression;" 1560s, "act of reciprocating," from Latin reciprocationem (nominative reciprocatio) "retrogression, alternation, ebb," noun of action from past participle stem of reciprocare "move back, turn back," also "come and go, move back and forth;" from reciprocus (see reciprocal).
reciprocity (n.): 1766, from French réciprocité (18c.), from reciproque, from Latin reciprocus, past participle of reciprocare (see reciprocal).
recision (n.): "act of cutting off," 1610s, from Middle French recision, alteration of rescision (from Late Latin rescissionem "annulment;" see rescission), influenced in form by Late Latin recisionem (nominative recisio) "a cutting back," noun of action from past participle stem of recidere "to cut back" (see recidivist).
recital (n.): 1510s, a legal term, "rehearsal or statement of relevant facts," from recite + -al. Meaning "act of reciting" is from 1610s; musical performance sense is from 1811.
recitation (n.): late 15c., "act of detailing," from Old French récitation (14c.) and directly from Latin recitationem (nominative recitatio) "public reading, a reading aloud," noun of action from past participle stem of recitare (see recite). Meaning "act of repeating aloud" is from 1620s; that of "repetition of a prepared lesson" is first recorded 1770, American English.
recitative (n.): "style of musical declamation intermediate between speech and singing, form of song resembling declamation," 1650s, from Italian recitativo, from recitato, past participle of recitare, from Latin recitare "read out, read aloud" (see recite). From 1640s as an adjective. The Italian form of the word was used in English from 1610s.
recite (v.): early 15c., from Old French reciter (12c.) and directly from Latin recitare "read aloud, read out, repeat from memory, declaim," from re- "back, again" (see re-) + citare "to summon" (see cite). Related: Recited; reciting.
reck (v.): Old English reccan (2) "take care of, be interested in, care for; have regard to, take heed of; to care, heed; desire (to do something)" (strong verb, past tense rohte, past participle rought), from West Germanic *rokjan, from Proto-Germanic *rokja- (cf. Old Saxon rokjan, Middle Dutch roeken, Old Norse rækja "to care for," Old High German giruochan "to care for, have regard to," German geruhen "to deign," which is influenced by ruhen "to rest").
And in that very moment, away behind in some courtyard of the city, a cock crowed. Shrill and clear he crowed, recking nothing of war nor of wizardry, welcoming only the morning that in the sky far above the shadows of death was coming with the dawn. [J.R.R. Tolkien, "Return of the King," 1955]
The -k- sound is probably a northern influence from Norse. No known cognates outside Germanic. "From its earliest appearance in Eng., reck is almost exclusively employed in negative or interrogative clauses" [OED]. Related: Recked; recking.
reck (n.): "care, heed, consideration," 1560s, from reck (v.).
reckless (adj.): Old English receleas "careless, thoughtless, heedless," earlier reccileas, from *rece, recce "care, heed," from reccan "to care" (see reck (v.)) + -less. The same affixed form is in German ruchlos, Dutch roekeloos "wicked." Root verb reck (Old English reccan) is passing into obscurity.
recklessly (adv.): Old English recceleaslice; see reckless + -ly (2).
recklessness (n.): Old English recceleasnes "recklessness, carelessness, negligence;" see reckless + -ness.
reckon (v.): c.1200, recenen, from Old English gerecenian "to explain, relate, recount," from West Germanic *(ga)rekenojanan (cf. Old Frisian rekenia, Middle Dutch and Dutch rekenen, Old High German rehhanon, German rechnen, Gothic rahnjan "to count, reckon"), from Proto-Germanic *rakinaz "ready, straightforward," from PIE *reg- "to move in a straight line," with derivatives meaning "direct in a straight line, rule" (see regal).

Intransitive sense "make a computation" is from c.1300. In I reckon, the sense is "hold an impression or opinion," and the expression, used parenthetically, dates from c.1600 and formerly was in literary use (Richardson, etc.), but came to be associated with U.S. Southern dialect and was regarded as provincial or vulgar. Related: Reckoned; reckoning.
reckoner (n.): early 13c., agent noun from reckon. Especially "book of tables used in calculation," often known as a ready reckoner.
reckoning (n.): early 14c., "narrative, account," verbal noun from reckon (v.). Meaning "a settling of accounts" is from mid-14c.; that of "calculation" is from late 14c. Cf. Dutch rekening "a bill, account, reckoning," Old High German rechenunga, German rechnung, Danish regning "a reckoning, computation."
reclaim (v.): early 14c., "call back a hawk to the glove," from Old French reclamer "to call upon, invoke; claim; seduce; to call back a hawk" (12c.) and directly from Latin reclamare "cry out against, contradict, protest, appeal," from re- "opposite, against" (see re-) + clamare "cry out" (see claim (v.)).

"Call back a hawk," hence "to make tame" (mid-15c.), "subdue, make amenable to control." In many Middle English uses with no sense of return or reciprocation. Meaning "revoke" (a grant, gift, etc.) is from late 15c. Sense of "get back by effort" might reflect influence of claim. Meaning "bring waste land into useful condition fit for cultivation" first attested 1764, probably on notion of "reduce to obedience." Related: Reclaimed; reclaiming.
reclamation (n.): late 15c., "a revoking" (of a grant, etc.), from Old French réclamacion and directly from Latin reclamationem (nominative reclamatio) "a cry of 'no,' a shout of disapproval," noun of action from past participle stem of reclamare "cry out against, protest" (see reclaim).
recline (v.): early 15c., from Old French recliner "rest, lay; bend, lean over" (13c.) and directly from Latin reclinare "to bend back, to lean back; cause to lean," from re- "back, against" (see re-) + clinare "to bend," from PIE *klei-n-, suffixed form of *klei "to lean" (see lean (v.)). Related: Reclined; reclining.
Recline is always as strong as lean, and generally stronger, indicating a more completely recumbent position, and approaching lie. ["Century Dictionary"]
recliner (n.): 1660s, agent noun from recline. From 1880 as a type of chair.
recluse (n.): c.1200, "person shut up from the world for purposes of religious meditation," from Old French reclus (fem. recluse) "hermit, recluse," also "confinement, prison; convent, monastery," noun use of reclus (adj.) "shut up," from Late Latin reclusus, past participle of recludere "to shut up, enclose" (but in classical Latin "to throw open"), from Latin re-, intensive prefix, + claudere "to shut" (see close (v.)).
reclusive (adj.): 1590s, from recluse + -ive. Recluse formerly served also as an adjective in English.
recognise (v.): chiefly British English spelling of recognize; for spelling, see -ize. Related: Recognised; recognising; recognisance.
recognition (n.): late 15c., from Latin recognitionem (nominative recognitio) "act of recognizing," noun of action from past participle stem of recognoscere "to acknowledge, know again, examine" (see recognize).
recognizance (n.): late 14c., reconyssaunce, from Old French reconissance "acknowledgment, recognition" (French reconnaissance), from present participle stem of reconoistre (see recognize). Related: Recognizant.
recognization (n.): 1550s, from recognize + -ation.
recognize (v.): early 15c., "resume possession of land," from Middle French reconiss-, stem of reconoistre "to know again, identify, recognize," from Old French, from Latin recognoscere "acknowledge, recall to mind, know again, examine, certify," from re- "again" (see re-) + cognoscere "know" (see cognizance). Meaning "perceive something or someone as already known" first recorded 1530s. Related: Recognized; recognizing.
recoil (n.): c.1300, "retreat," from recoil (v.).
recoil (v.): early 13c., "force back, drive back," from Old French reculer "to go back, recede, retreat," from Vulgar Latin *reculare, from Latin re- "back" (see re-) + culus "backside." Meaning "shrink back, retreat" is first recorded c.1300; and that of "spring back" (as a gun) in 1520s. Related: Recoiled; recoiling.
recollect (v.): 1550s, from Latin recollectus, past participle of recolligere, literally "to collect again," from re- "again" (see re-) + colligere "gather" (see collect). Related: Recollected; recollecting.
recollection (n.): 1590s, "a gathering together again," from French récollection or Medieval Latin recollectionem, noun of action from recolligere (see recollect). Meaning "act of recalling to memory" is from 1680s; a thing or scene so recalled, from 1781.
recombinant (adj.): 1942, from recombine + -ant.
recombination (n.): 1791, from re- + combination.
recombine (v.): by 1758; see re- + combine (v.). Related: Recombined; recombining.