Slash
late Middle English: perhaps imitative, or from Old French esclachier ‘break in pieces’. The noun dates from the late 16th century.
wiktionary
Originally a verb of uncertain etymology. Possibly from French esclachier(“to break”). Used once in the Wycliffe Bible as slascht but otherwise unattested until 16th century. Conjunctive use from various applications of the punctuation mark ⟨ /⟩. See also slash fiction.
Of uncertain etymology. Compare Scots slash(“ large splash”), possibly from Old French esclache. Slang use for urination attested from the 1950s.
Of uncertain etymology. Compare flash(“a marsh; a pool of water”) and British dialectal slashy(“ wet and dirty, miry”).
See slatch
etymonline
slash (v.)
1540s, "to cut with a stroke of a blade or whip;" 1650s, "to strike violently," perhaps from French esclachier "to break," variant of esclater "to break, splinter" (see slat). Meaning "to clear land" (of trees) is from 1821, American English. In reference to prices, it is attested from 1906. Related: Slashed; slashing. Slash-and-burn for a method of clearing forest for cultivation is from 1919.
slash (n.)
"a cutting stroke with a weapon," 1570s, from slash (v.); sense of "slit in a garment" is from 1610s; that of "open tract in a forest" is first attested 1825, American English. As a punctuation mark in writing or printing, it is recorded from 1961.
