early 13c., in frere menour "Franciscan friar," literally "minor friar," from Latin minor "less, lesser, smaller, junior," figuratively "inferior, less important," which was formed as a masculine/feminine form of minus on the mistaken assumption that minus was a neuter comparative, from PIE root *mei- (2) "small." Compare minor (n.). In some cases the English word is from Old French menor "less, smaller, lower; underage, younger," from Latin minor.
Meaning "underage" is from 1570s. Meaning "lesser or smaller (than the other)" in English is from early 15c.; that of "comparatively less important" is from 1620s. The musical sense is from 1690s in reference to intervals (and to tonalities and scales characterized by a minor third), so called because the interval is lesser or shorter than the corresponding major interval. Of triads or chords by 1797; their emotional effect is notable mournful, mysterious, gloomy, or wistful, hence figurative and extended senses. In the baseball sense, minor league, made up of teams below the major league, is from 1884; the figurative extension of that is recorded by 1926.
early 14c., Menour, "a Franciscan," from Latin Fratres Minores "lesser brethren," name chosen by the order's founder, St. Francis, for the sake of humility; see minor (adj.). From c. 1400 as "minor premise of a syllogism." From 1610s as "person of either sex who is under legal age for the performance of certain acts" (Latin used minores (plural) for "the young"). Musical sense is from 1797 (see the adjective). Academic meaning "secondary subject of study, subject of study with fewer credits than a major" is from 1890; as a verb in this sense by 1905.
c. 1600, "part or character one takes," from French rôle "part played by a person in life," literally "roll" (of paper) on which an actor's part is written, from Old French rolle (see roll (n.)). Not originally in English with direct reference to actors and the stage, but figurative of them. The meaning "any conspicuous function performed characteristically by someone" is by 1875. In the social psychology sense is from 1913. Role model, one taken by others as a model in performance of some role, is attested by 1957.
also re-cast, c. 1600, "to throw again," from re- "back, again" + cast (v.). Sense of "to cast or form anew, remodel," especially of literary works and other writing, is from 1790. Meaning "compute anew" is by 1865. Theater sense of "assign an actor or role to another role or actor" is by 1951. Related: Recasting. As a noun, "a fresh molding, arrangement, or modification," by 1840.
by 1979, initialism (acronym) from role-playing game (see roleplay). As an initialism for rocket-propelled grenade, by 1970.
late 14c., peti, "small, little, minor," from a phonemic spelling of Old French petit "small" (see petit). From late 12c. in surnames. In English, not originally disparaging (as still in petty cash "small sums of money received or paid," 1834; petty officer "minor or inferior military officer," 1570s).
Meaning "of small or minor importance, not serious" is recorded from 1520s; that of "small-minded" is from 1580s. Related: Pettily; pettiness.