"a razor," by 1915, possibly 1890s or earlier in underworld slang, a variant (based on pronunciation) of chive, thieves' cant word for "knife" (1670s), of unknown origin. Often said to be a Romany (Gypsy) word, from chivomengro "knife."
shit
shite
shithead
shitten
shitty
shiv
shiva
shivah
shivaree
shive
shiver