capitulate (v.)

1590s, “to draw up a writing in chapters or articles” (i.e., under “headings”), in part a back-formation from capitulation (q.v.), in part from Medieval Latin capitulatus, past participle of capitulare “to draw up in heads or chapters,” hence “arrange conditions,” from capitulum “chapter,” in classical Latin “heading,” literally “a little head,” diminutive of caput (genitive capitis) “head” (from PIE root *kaput- “head”).

Often of terms of surrender, and thus it came to mean “to yield to an enemy on stipulated terms” (1680s). Related: Capitulatedcapitulating. Compare chapter.

linchpin (n.)

also linch-pin, “peg that holds a wheel on an axle” (now mainly figurative), late 14c., a corruption of linspin, literally “axle-pin,” from pin (n.) + from Middle English lins “axle,” from Proto-Germanic *luniso (source also of Old Saxon lunisa, Middle Dutch lunse, Dutch luns, German Lünse), a word of uncertain origin.

countenance (n.)

mid-13c., contenaunce, “behavior, bearing, conduct, manners;” early 14c., “outward appearance, looks,” from Old French contenance “demeanor, bearing, conduct,” from Latin continentia “restraint, abstemiousness, moderation,” literally “way one contains oneself,” from continentem, present participle of continere “to hold together, enclose,” from assimilated form of com “with, together” (see con-) + tenere “to hold,” from PIE root *ten- “to stretch.”

The meaning evolved in late Middle English from “appearance” to “facial expression betraying or expressing a state of mind,” to “the face” itself. Hence also, figuratively, “aspect imparted to anything.”

beneficiary

1610s (n.) “one who receives profits or advantages,” 1620s (adj.) “connected with the receipt of profits or advantages,” probably via French bénéficiaire, from Latin beneficiarius “enjoying a favor, privileged,” from beneficium “a favor, service, generosity, kindness, benefit,” from beneficus “generous, kind, benevolent, obliging,” from bene- “good, well” (see bene-) + -ficus “making, doing,” from -ficere, combining form of facere “to do, to make” (from PIE root *dhe- “to set, put”).

affidavit (n.)

“written declaration upon an oath,” 1590s, from Medieval Latin affidavit, literally “he has stated on oath,” third person singular perfective of affidare “to trust; to make an oath,” from Latin ad “to” (see ad-) + fidare “to trust,” from fidus “faithful,” from PIE root *bheidh- “to trust, confide, persuade.” So called from being the first word of sworn statements.

certiorari (n.)

“writ from superior to inferior courts seeking the records of a case,” legal Latin, “to be certified, to be informed or shown,” a word figuring in the opening phrase of such writs; passive present infinitive of certorare “to certify, inform,” from certior, comparative of certus “sure” (see certain).