gear (n.) Look up gear at Dictionary.com
c.1200, "fighting equipment," probably from Old Norse gervi "apparel," related to gerr "ready," and gerva "make ready," from Proto-Germanic *garwian- "to make, prepare, equip" (cognates: Old English gearwe "clothing, equipment, ornament;" Dutch gaar "done, dressed;" Old High German garo "ready, prepared, complete," garawi "clothing, dress," garawen "to make ready;" German gerben "to tan"). Meaning "toothed wheel in machinery" first attested 1520s. Slang for "male sex organs" from 1670s. British adjective slang sense of "stylish, excellent" first recorded 1951, from earlier that's the gear, expression of approval, 1925.
gear (v.) Look up gear at Dictionary.com
c.1200, "to equip oneself for fighting; dress," probably from gear (n.). Related: Geared; gearing.