- re-
- prefix1》 once more; afresh; anew: reactivate.↘with return to a previous state: restore.2》 (also red-) in return; mutually: resemble.↘in opposition: repel.3》 behind or after: relic.↘in a withdrawn state: reticent.↘back and away; down: recede.4》 with frequentative or intensive force: resound.5》 with negative force: recant.Originfrom L. re-, red- 'again, back'.UsageWords formed with re- tend to be unhyphenated: restore, reacquaint. An exception to this occurs when the word to which re- attaches begins with e, in which case a hyphen is often inserted for clarity: re-examine, re-enter. A hyphen is sometimes also used where the word formed with the prefix would be identical to an already existing word: re-cover (meaning ‘cover again’) not recover (meaning ‘get better in health’).
English new terms dictionary. 2014.