Middle English slēn, "strike, beat, strike so as to kill, commit murder," from Old English slean "to smite, strike, beat," also "to kill with a weapon, slaughter" (class VI strong verb; past tense sloh, slog, past participle slagen), from Proto-Germanic *slahanan "to hit" (source also of Old Norse and Old Frisian sla, Danish slaa, Middle Dutch slaen, Dutch slaan, Old High German slahan, German schlagen, Gothic slahan "to strike"). The Germanic words are said to be from PIE root *slak- "to strike" (source also of Middle Irish past participle slactha "struck," slacc "sword"), but, given certain phonetic difficulties and that the only cognates are Celtic, Boutkan says the evidences "point to a North European substratum word."

The verb slēn displays many nondialectal stem variants because of phonological changes and analogical influences both within its own paradigm and from other strong verbs. [Middle English Compendium]

Modern German cognate schlagen maintains the original sense of "to strike."

It is attested by late 12c. as "destroy, put an end to." The meaning "overwhelm with delight" (mid-14c.) preserves one of the wide range of meanings the word once had, including, in Old English, "stamp (coins); forge (weapons); throw, cast; pitch (a tent), to sting (of a snake); to dash, rush, come quickly; play (the harp); gain by conquest."

1940, in reference to military raids, etc., from hit (v.) + run (v.). As a noun phrase, Hit and run is from 1899 as a baseball play, 1924 as a driver failing to stop at an automobile accident he caused.

"hired assassin," 1970, from hit (n.) in the underworld sense + man (n.).

"at random," c.1600, from hit (v.) + miss (v.).

baseball term for a baseball game in which one side fails to make a hit, 1939, from no + hit (n.).

1580s, "act of striking, a blow or darting at a prey," from strike (v.). The earlier noun was striking (n.), c. 1400.

The meaning "coordinated cessation of work by a body of employees" is from 1810 (in general strike). The extended sense (as in hunger strike) is by 1889. Strike-breaker "scab" is by 1904.

In baseball the word is recorded from 1841, originally "a hit, contact with the ball," no matter where it went. A hit ball that didn't land in fair play was a foul strike (by 1874, what would later be a foul ball), and it counted against the batter as a miss. As hit (n.) came to be used for "contact that puts the ball in play" and may score runs, strike was left for "a foul strike" as well as "a swing and a miss" both of which count against the batter.

These senses emerged by 1890s: in reference to the batter, "an unsuccessful attempt to hit the ball," 1896; and, in reference to the pitcher, "a ball so pitched to pass over home plate and which the umpire considers the batter should have swung at," 1891.

The figurative sense of having two strikes against (of a possible three), "be down to ones last opportunity" is from 1938. Strike zone, "imaginary rectangle with the batter's shoulders and knees as its top and bottom and home plate's edges as its sides," is by 1927. Compare the baseball shorthand use of K for "strikeout."

The bowling sense (also sometimes ten-strike), "a knocking down of all the pins with one ball" is attested by 1859. The meaning "sudden military attack" is attested from 1942.

by 1919 in baseball slang, "ambidextrous batter, one who bats right- or left-handed;" see switch (n.), used adjectivally, + hit (v.). It is attested by 1956 in the colloquial slang sense of "bisexual person." Related: Switch-hitting.

A natural left-hand hitter never experiments from the other side of the plate. A right-hand batter who finds he is a sucker for a right-hand pitcher's curve ball becomes a switch-hitter for self protection. [Al Demaree, "Southpaws Swear at Switch-Hitters," Corsicana (Texas) Daily Sun, Feb. 7, 1935]