reprieve v.

late 14c., "yearly deduction from charges upon a manor or estate," from Old French reprise "act of taking back" (13c.), fem. of repris, past participle of reprendre "take back," from Latin reprendere"pull back, hold back" (see reprehend). The meaning "resumption of an action" is attested from 1680s. The musical sense of "a repeated passage, act of repeating a passage" is by 1879.

early 14c., acheven, "to perform, execute, accomplish;" late 14c., "gain as a result of effort," from Old French achever (12c.) "to finish, accomplish, complete," from phrase à chef (venir) "at an end, finished," or Vulgar Latin *accapare, from Late Latin ad caput (venire); both the French and Late Latin phrases meaning literally "to come to a head," from ad "to" (see ad-) + stem of Latin caput "head" (from PIE root *kaput- "head").

The Lat. caput, towards the end of the Empire, and in Merov[ingian] times, took the sense of an end, whence the phrase ad caput venire, in the sense of to come to an end .... Venire ad caput naturally produced the Fr. phrase venir à chef = venir à bout. ... From this chief, O.Fr. form of chef (q.v.) in sense of term, end, comes the Fr. compd. achever = venir à chef, to end, finish. [Auguste Brachet, "An Etymological Dictionary of the French Language," transl. G.W. Kitchin, Oxford, 1878]

Related: Achieved; achieving.

also *ghed-, Proto-Indo-European root meaning "to seize, to take." 

It forms all or part of: apprehend; apprentice; apprise; beget; comprehend; comprehension; comprehensive; comprise; depredate; depredation; emprise; enterprise; entrepreneur; forget; get; guess; impresario; misprision; osprey; predatory; pregnable; prehensile; prehension; prey; prison; prize (n.2) "something taken by force;" pry (v.2) "raise by force;" reprehend; reprieve; reprisal; reprise; spree; surprise.

It is the hypothetical source of/evidence for its existence is provided by: Greek khandanein "to hold, contain;" Lithuanian godėtis "be eager;" second element in Latin prehendere "to grasp, seize;" Welsh gannu "to hold, contain;" Russian za-gadka "riddle;" Old Norse geta "to obtain, reach; to be able to; to beget; to learn; to be pleased with;" Albanian gjen "to find."