Online Etymology Dictionary

re-align (v.): also realign, 1876 in reference to railroad tracks; 1923, in reference to European international relations, from re- "back, again" + align. Related: Realigned; realigning.
re-alignment (n.): also realignment, 1850, from re- + alignment.
re-allocate (v.): also reallocate, by 1868, from re- + allocate. Related: Reallocated; reallocating.
re-allocation (n.): also reallocation, 1931, noun of action from reallocate (v.).
re-ally (v.): "to form an alliance again," c.1600, from re- + ally (v.). Related: Re-allied.
re-animate (v.): also reanimate, 1610s, in spiritual and physical sense, from re- "back, again" + animate (v.) "to endow with life." Related: Reanimated; reanimating.
re-animation (n.): also reanimation, 1797, from re- + animation.
re-appear (v.): also reappear, 1610s, from re- "back, again" + appear. Related: Reappeared; reappearing.
re-appearance (n.): also reappearance, 1660s; see reappear + -ance.
re-apply (v.): also also reapply, 1723, from re- + apply. Related: Reapplied; reapplying.
re-apportion (v.): also reapportion, 1832, from re- + apportion. Related: Reapportioned; reapportioning.
re-apportionment (n.): also reapportionment, 1800, American English, from re- + apportionment.
re-arm (v.): also rearm, 1805 (implied in re-arming), from re- "back, again" + arm (v.) "to supply with arms." Related: Re-armed.
re-armament (n.): also rearmament, 1864; see re- + armament.
re-arrange (v.): also rearrange, 1798, from re- "back, again" + arrange. Related: Rearranged; rearranging; rearrangement.
re-assemble (v.): also also reassemble, late 15c., from re- + assemble. Related: Reassembled; reassembling; reassembler; reassembly.
re-assert (v.): also also reassert, 1660s, from re- + assert. Related: Reasserted; reasserting; reassertion.
re-assess (v.): also also reassess, 1803; see re- + assess. Related: Reassessed; reassessing.
re-assessment (n.): also also reassessment, 1751, from re- + assessment.
re-awaken (v.): also reawaken, 1810, from re- + awaken. Related: Reawakened; reawakening.
re-cover (v.): "to put a new cover on," c.1400, from re- "again" + cover (v.). Related: Re-covered; re-covering.
re-create (v.): also recreate, "to create anew," 1580s, from re- "back, again" + create. Related: Re-created; re-creating; re-creation.
re-elect (v.): also reelect, c.1600, from re- "back, again" + elect (v.). Related: Re-elected; re-electing.
re-enact (v.): also reenact, 1670s, from re- "back, again" + enact. Originally of laws, etc.; meaning "to perform again, reproduce" is recorded from 1854. Related: Re-enacted; re-enacting.
re-enactment (n.): also reenactment, 1780; see re-enact + -ment.
re-enforce (v.): also reenforce, 1580s, "to give fresh strength to," from re- "back, again" + enforce (v.). Originally of persons or military units; of buildings, structures, etc., attested from 1883. Related: Re-enforced; re-enforcing.
re-enlist (v.): also reenlist, 1828, from re- "back, again" + enlist. Related: Re-enlisted; re-enlisting.
re-entry (n.): also reentry, mid-15c., "act of entering again," from re- "again" + entry; probably on model of Middle French rentrer (12c.). Specifically of spacecraft from 1948.
re-establish (v.): also reestablish, late 15c.; from re- + establish. Related: Re-established; re-establishing.
re-evaluate (v.): also reevaluate, 1903, from re- + evaluate. Related: Reevaluated; reevaluating.
re-evaluation (n.): also reevaluation, 1905; noun of action from re-evaluate.
re-examine (v.): also reexamine, 1590s, from re- + examine. Related: Re-examined; re-examining.
re-up (v.): "to re-enlist," 1906, U.S. armed forces slang, from re- "back, again" + up (v.) "enlist." Related: Re-upped; re-upping.
reach (v.): Old English ræcan, reccan "reach out, stretch out, extend, hold forth," also "succeed in touching, succeed in striking; address, speak to," also "offer, present, give, grant," from West Germanic *raikjan "stretch out the hand" (cf. Old Frisian reka, Middle Dutch reiken, Dutch reiken, Old High German and German reichen), from Proto-Germanic *raikijanau, perhaps from PIE root *reig- "to stretch out" (cf. Sanskrit rjyati "he stretches himself," riag "torture" (by racking); Greek oregein "to reach, extend;" Lithuanian raižius "to stretch oneself;" Old Irish rigim "I stretch").

Shakespeare uses the now-obsolete past tense form raught (Old English ræhte). Meaning "arrive at" is early 14c.; that of "succeed in influencing" is from 1660s. Related: Reached; reaching. Reach-me-down "ready-made" (of clothes) is recorded from 1862, from notion of being on the rack in a finished state.
reach (n.): 1520s, from reach (v.); earliest use is of stretches of water. Meaning "extent of reaching" is from 1540s; that of "act of reaching" is from 1560s.
Ah, but a man's reach should exceed his grasp,
Or what's a heaven for?

[Browning, "Andrea del Sarto"]
react (v.): 1640s, "to exert, as a thing acted upon, an opposite action upon the agent," from re- + act (v.). Chemical sense is from 1944. Related: Reacted; reacting (1610s). For sense development, see reaction. Meaning "perform again" (often re-act) is from 1650s.
reactant: 1901 (n.), 1911 (adj.), from react + -ant.
reaction (n.): "action in resistance or response to another action or power," 1610s, from re- "again, anew" + action (q.v.). Modeled on French réaction, older Italian reattione, from Medieval Latin reactionem (nominative reactio), noun of action formed in Late Latin from past participle stem of Latin reagere "react," from re- "back" + agere "to do, act" (see act (v.)).

Originally scientific; physiological sense is attested from 1805; psychological sense first recorded 1887; general sense of "action or feeling in response" (to a statement, event, etc.) is recorded from 1914. Reaction time, "time elapsing between the action of an external stimulus and the giving of a signal in reply," attested by 1874.
reactionary (adj.): 1831, on model of French réactionnaire (19c.), from réaction (see reaction). In Marxist use, "tending toward reversing existing tendencies," opposed to revolutionary and used opprobriously in reference to opponents of communism, by 1858. As a noun, "person considered reactionary," especially in politics, one who seeks to check or undo political action, by 1855.
reactivate (v.): 1902, from re- "back, again" + activate. Related: Reactivated; reactivating; reactivation.
reactive (adj.): 1712, from react + -ive. Related: Reactively; reactiveness; reactivity.
reactor (n.): "one that reacts," 1835, agent noun in Latin form from react. In nuclear sense, attested from 1945.
read (v.): Old English rædan (West Saxon), redan (Anglian) "to advise, counsel, persuade; discuss, deliberate; rule, guide; arrange, equip; forebode; read, explain; learn by reading; put in order" (related to ræd, red "advice"), from Proto-Germanic *raedanan (cf. Old Norse raða, Old Frisian reda, Dutch raden, Old High German ratan, German raten "to advise, counsel, guess"), from PIE root *re(i)- "to reason, count" (cf. Sanskrit radh- "to succeed, accomplish," Greek arithmos "number amount," Old Church Slavonic raditi "to take thought, attend to," Old Irish im-radim "to deliberate, consider"). Words from this root in most modern Germanic languages still mean "counsel, advise."

Sense of "make out the character of (a person)" is attested from 1610s. Connected to riddle via notion of "interpret." Transference to "understand the meaning of written symbols" is unique to Old English and (perhaps under English influence) Old Norse raða. Most languages use a word rooted in the idea of "gather up" as their word for "read" (cf. French lire, from Latin legere). Read up "study" is from 1842; read out (v.) "expel by proclamation" (Society of Friends) is from 1788. read-only in computer jargon is recorded from 1961.
read (adj.): 1580s, "having knowledge gained from reading," in well-read, etc., past participle adjective from read (v.).
read (n.): "an act of reading," 1825, from read (v.).
read-out (n.): 1946, in computer sense, from read (v.) + out (adv.).
readability (n.): 1829, from readable + -ity.
readable (adj.): 1560s, from read (v.) + -able. Related: Readably.
reader (n.): Old English rædere "person who reads aloud to others; lector; scholar; diviner, interpreter," agent noun from rædan (see read (v.)). Cf. Dutch rader "adviser," Old High German ratari "counselor." Old English fem. form was rædistre.
readership (n.): 1719, "office of a reader," from reader + -ship. Meaning "total number of readers of a publication" is from 1914.