"to mend, put back in order, restore to a sound, good, or complete condition," mid-14c., reparen, from Old French reparer "repair, mend" (12c.) and directly from Latin reparare "restore, put back in order," from re- "again" (see re-) + parare "make ready, prepare" (from PIE root *pere- (1) "to produce, procure").
The sense of "make amends for injury by an equivalent, make good" is by 1560s. Related: Repaired; repairing.
c. 1300, repairen, "go (to a specified place), arrive, make one's way, betake oneself," from Old French repairer, repairier "to return, come back, to frequent, to return (to one's country)," earlier repadrer, from Late Latin repatriare "return to one's own country" (see repatriate). Related: Repaired; repairing; repairment.
c. 1400, repaire, "maintenance, restoration;" 1590s, "act of restoring, restoration to a sound or good state after decay," from repair (v.1). Meaning "state or condition in respect to reparation" is from c. 1600, especially "good or sound condition kept up by repairing as needed." Repair-shop attested by 1877.
early 14c., "act of betaking (oneself) to a (specific) place," from repair (v.2). Sense of "place to which one repairs, a haunt or resort" is from late 14c.
early 15c., from Old French irréparable (12c.), from Latin irreparabilis "not to be repaired or recovered," from assimilated form of in- "not, opposite of" (see in- (1)) + reparabilis "that can be repaired" (see repair (v.)). Irrepairable, from the English verb, was used 16c.-17c. but seldom was seen after.
late 14c., reparacioun, "repair, act of mending" (a sense now rare or obsolete), also "amends, compensation, recompense, satisfaction for injury, what is done to repair a wrong," from Old French reparacion and directly from Late Latin reparationem (nominative reparatio) "act of repairing, restoration," noun of action from past-participle stem of Latin reparare "restore, repair" (see repair (v.1)).
Reparations "compensation for war damaged owed by the aggressor" is attested from 1921, with reference to Germany, from French réparations (1919).
"capable of being repaired," 1560s, from French reparable (16c.), from Latin reparabilis "able to be restored or regained," from reparare "restore" (see repair (v.1)). Fowler (1926) notes that reparable "is used almost only of abstracts, such as loss, injury, mistake, which are to be made up for or have their effects neutralized," while repairable is used "chiefly of material things that need mending."