task-force (n.)

early 14c., "a quantity of labor imposed as a duty," from Old North French tasque (12c., Old French tasche, Modern French tâche) "duty, tax," from Vulgar Latin *tasca "a duty, assessment," metathesis of Medieval Latin taxa, a back-formation of Latin taxare "to evaluate, estimate, assess" (see tax (v.)). General sense of "any piece of work that has to be done" is first recorded 1590s. Phrase take one to task (1680s) preserves the sense that is closer to tax.

German tasche "pocket" is from the same Vulgar Latin source (via Old High German tasca), with presumable sense evolution from "amount of work imposed by some authority," to "payment for that work," to "wages," to "pocket into which money is put," to "any pocket."

c. 1300, "physical strength," from Old French force "force, strength; courage, fortitude; violence, power, compulsion" (12c.), from Vulgar Latin *fortia (source also of Old Spanish forzo, Spanish fuerza, Italian forza), noun use of neuter plural of Latin fortis "strong, mighty; firm, steadfast; brave, bold" (see fort).

Meanings "power to convince the mind" and "power exerted against will or consent" are from mid-14c. Meaning "body of armed men, a military organization" first recorded late 14c. (also in Old French). Physics sense is from 1660s; force field attested by 1920. Related: Forces.