internal security force of Nazi Germany, 1930, German, literally "defense squadron." Better known by its initials, S.S.

1520s, "obtain by force or compulsion; wrest away by oppressive means," from Latin extortus, past participle of extorquere "obtain by force," literally "to wrench out," from ex "out" (see ex-) + torquere "to twist" (from PIE root *terkw- "to twist"). Related: Extorted; extorting. As a past-participle adjective from early 15c.

"to force together one inside the other" (like the sliding tubes of some telescopes), 1867, from telescope (n.). Related: Telescoped; telescoping.

"nine-point scale for test scores," introduced by the U.S. Air Force in 1942, from sta(ndard) + nine.

1827 of animals (1805 of plants), from spine + -less. Meaning "lacking moral force" is from 1885. Related: Spinelessly; spinelessness.

1560s, from Italian squadrone, augmentative of squadra "battalion," literally "square" (see squad). As a division of a fleet, from 1580s, of an air force, 1912.

"any structure serving to break the force of waves and protect a harbor or shore," 1721; see break (v.) + water (n.1).

"derived from the force or motion of fluid," 1815, from hydro- + dynamic (adj.). Related: Hydrodynamics (1764), from Modern Latin hydrodynamica (Huberti, 1758).

"with violence, strength, or force," 1530s, from main (adj.) by analogy with other words in a- (such as afoot).

mid-13c., "a bringing by force," verbal noun from lead (v.1). Meaning "direction, guidance" is from late 14c.