re- repr. L. re-, (before a vowel in the classical period) red- (e.g. redimere REDEEM, redundāre REDOUND); pref. restricted to the Italic group, having the general sense of ‘back’ or ‘again’, occurring in many Eng. words of L. or Rom. origin (cf. F. re-, ré-, Sp., Pg. re-, It. ri-), or of Eng. formations freely modelled on these. From the L. was derived an adj. *recos, repr. in reciprocus RECIPROCAL, and an adv. retrō backwards, RETRO-. In combination with a- the prefix is disguised in rally, rampart, and ransom, and in the non-naturalized rallentando, rapport, rapprochement. The meanings of the L. prefix, which are all repr. in Eng., are:
1.. backwards from a point reached or to the starting-point, e.g. recēdere RECEDE, revocāre REVOKE; passing sometimes into ‘away’, e.g. removēre REMOVE;

2.. back to an earlier state or over to another condition, e.g. renovāre RENOVATE, resūmere RESUME;

3.. back in a place, from going forward, e.g. residēre RESIDE, retinēre RETAIN;

4.. again, in return, (the most frequent use in new formations);

5.. in a contrary direction, so that what has been done is annulled or destroyed ( = UN-2), e.g. renuntiāre RENOUNCE, revēlāre unveil, REVEAL1;

6.. in opposition or conflict, e.g. rebellis REBEL, recrīminārī RECRIMINATE;

7.. in response to a stimulus, with intensive force, e.g. requīrere REQUIRE, resolvere RESOLVE
.

Words containing the prefix occur as early as c.1200 and become more frequent in XIV; it became an Eng. pref. in XVI, formations on native words being modelled to some extent on foreign comps., as recall on L. revocāre, recast after F. refondre. There are double forms with different meanings (with or without hyphen) arising from the coining of new formations from els. identical with those of already existing ones, e.g. re-cover (cover again) beside RECOVER.