Political sense is first recorded 1734, and negative overtones began with its association with Irish patriots such as Daniel O'Connell (1775-1847). Historically, in American English, often with outside and referring to people who stir up a supposedly contented class or race. Latin agitator meant "a driver, a charioteer."
plural of stirps, Latin, literally "stem, stalk, trunk of a plant," figuratively "scion, offspring, descendant; source, origin, foundation, beginning," a word of uncertain origin. Hence stirpiculture "breeding of special stocks or strains."
c. 1300, blenden, "to mix in such a way as to become inextinguishable, mingle, stir up a liquid," in northern writers, from or akin to rare Old English blandan "to mix" (Mercian blondan) or Old Norse blanda "to mix," or a combination of the two; from Proto-Germanic *blandan "to mix," which comes via a notion of "to make cloudy" from an extended Germanic form of the PIE root *bhel- (1) "to shine, flash, burn."
Compare Old Saxon and Old High German blantan, Gothic blandan, Middle High German blenden "to mix;" German Blendling "bastard, mongrel," and, outside Germanic, Lithuanian blandus "troubled, turbid, thick;" Old Church Slavonic blesti "to go astray." Figurative sense of "mingle closely" is from early 14c. Related: Blended; blending.
c. 1300 (intransitive), "To make a quick sharp noise with frequent repetitions and collisions of bodies not very sonorous: when bodies are sonorous, it is called jingling" [Johnson]. Perhaps in Old English but not recorded; if not, from Middle Dutch ratelen, which is probably of imitative origin (compare German rasseln "to rattle," Greek kradao "I rattle").
The sense of "utter smartly and rapidly, speak with noisy and rapid utterance" is attested by late 14c. The meaning "to go along loosely and noisily" is from 1550s. The transitive sense is from late 14c. The colloquial American English figurative meaning of "fluster, shake up, unsettle" is attested by 1869, on the notion of "startle or stir up by noisy means." Related: Rattled; rattling.
mid-15c., rousen, intransitive, probably from Anglo-French or Old French reuser, ruser; Middle English Compendium compares 16c. French rousee "abrupt movement." Sometimes also said to be from Latin recusare "refuse, decline," with loss of the medial -c-. Originally in English a technical term in hawking, "to shaking the feathers of the body," but like many medieval hawking and hunting terms it is of obscure origin.
The sense of "cause game to rise from cover or lair" is from 1520s. The word became general from 16c. in the figurative, transitive, meaning "stir up, cause to start up by noise or clamor, provoke to activity; waken from torpor or inaction" (1580s); that of "to awaken, cause to start from slumber or repose" is recorded by 1590s. Related: Roused; rousing.
Old English awæcnan (intransitive), "to spring into being, arise, originate," also, less often, "to wake up;" earlier onwæcnan, from a- (1) "on" + wæcnan (see waken). Transitive meaning "to rouse from sleep" is recorded from 1510s; figurative sense of "stir up, rouse to activity" is from c. 1600.
Originally strong declension (past tense awoc, past participle awacen), already in Old English it was confused with awake (v.) and a weak past tense awæcnede (modern awakened) emerged and has since become the accepted form, with awoke and awoken transferred to awake. Subtle shades of distinction determine the use of awake or awaken in modern English. For distinctions of usage, see wake (v.). Related: Awakening.
The original sense was of motion, which led to that of lifting, then to that of "measure the weight of." The older sense of "lift, carry" survives in the nautical phrase weigh anchor. Figurative sense of "to consider, ponder" (in reference to words, etc.) is recorded from mid-14c. To weigh in in the literal sense is from 1868, originally of jockeys; figurative meaning "bring one's influence to bear" is from 1909.