gash (n.) Look up gash at Dictionary.com
1540s, alteration of Middle English garce "a gash, cut, wound, incision" (early 13c.), from Old North French garser "to scarify, cut, slash" (Old French *garse), apparently from Vulgar Latin *charassare, from Greek kharassein "engrave, sharpen, carve, cut," from PIE *gher- (4) "to scrape, scratch" (see character). Loss of -r- is characteristic (see ass (n.2)). Slang use for "vulva" dates to mid-1700s. Provincial English has a set of words (gashly, gashful, etc.) with forms from gash but senses from gast- "dreadful, frightful."
gash (v.) Look up gash at Dictionary.com
1560s, alteration of older garsh, from Middle English garsen (late 14c.), from Old North French garser "to cut, slash" (see gash (n.)). For loss of -r-, see ass (n.2). Related: Gashed; gashing.