Old English strican (past tense strac, past participle stricen) "pass lightly over, stroke, smooth, rub," also "go, move, proceed," from Proto-Germanic *strikan- (source also of Old Norse strykva "to stroke," Old Frisian strika, Middle Dutch streken, Dutch strijken "to smooth, stroke, rub," Old High German strihhan, German streichen), from PIE root *strig- "to stroke, rub, press" (see strigil). Related to streak and stroke, and perhaps influenced in sense development by cognate Old Norse striuka.
Sense of "to deal a blow" developed by early 14c.; meaning "to collide" is from mid-14c.; that of "to hit with a missile" is from late 14c. Meaning "to cancel or expunge" (as with the stroke of a pen) is attested from late 14c. A Middle English sense is preserved in strike for "go toward." Sense of "come upon, find" is from 1835 (especially in mining, well-digging, etc., hence strike it rich, 1854). Baseball sense is from 1853. To strike a balance is from the sense "balance accounts" (1530s).
Meaning "refuse to work to force an employer to meet demands" is from 1768, perhaps from notion of striking or "downing" one's tools, or from sailors' practice of striking (lowering) a ship's sails as a symbol of refusal to go to sea (1768), which preserves the verb's original sense of "make level, smooth."
1580s, "act of striking," from strike (v.). Meaning "concentrated cessation of work by a body of employees" is from 1810. Baseball sense is first recorded 1841, originally meaning any contact with the ball; modern sense developed by 1890s, apparently from foul strike, which counted against the batter, and as hit came to be used for "contact with the ball" this word was left for "a swing and a miss" that counts against the batter; figurative sense of have two strikes against (of a possible three) is from 1938. Bowling sense attested from 1859. Meaning "sudden military attack" is attested from 1942.