c. 1400, disclaimen, "renounce, relinquish, or repudiate a legal claim," originally in a feudal sense, from Anglo-French disclaimer(c. 1300), Old French desclamer "disclaim, disavow," from des- (see dis-) + clamer "to claim," from Latin clamare "to cry out, shout, proclaim," from PIE root *kele- (2) "to shout." Meaning "disavow any connection with, reject as not belonging to oneself" is from 1590s. Related: Disclaimed; disclaiming.
mid-15c., pretensioun, "assertion, allegation; objection; intention; signification," from Medieval Latin pretensionem (nominative pretensio), noun of action from past-participle stem of Latin praetendere "stretch in front, put forward, allege" (see pretend (v.)).
Meaning "unproven claim" is from c. 1600. The sense of "ostentation" is from 1727, from the notion of "act of putting forth a (false) claim to merit, dignity, or importance."
early 15c., assercioun, "a declaration, confirmation" from Old French assercion (14c.) or directly from Late Latin assertionem (nominative assertio), noun of action from past-participle stem of Latin asserere/adserere "to claim, lay claim to, appropriate," from ad "to" (see ad-) + serere "join together, put in a row" (from PIE root *ser- (2) "to line up"). By "joining oneself" to a particular view, one "claimed" or "maintained" it. From mid-15c. as "an unsupported statement."
c. 1300, from Anglo-French vengeaunce, Old French vengeance, venjance "revenge, retribution" (12c.), from vengier "take revenge," from Latin vindicare "assert a claim, claim as one's own; avenge, punish" (see vindicate).
Vengeance is mine, ... saith the Lord. Therefore if thine enemy hunger, feed him; if he thirst, give him drink; for in so doing thou shalt heap coals of fire upon his head. [Paul to the Romans, xii:19-20]
"act of taking more than one's due," 1590s, from Latin arrogationem (nominative arrogatio) "a taking to oneself," noun of action from past-participle stem of arrogare "to claim for oneself" (see arrogate).