mort (n.1) Look up mort at Dictionary.com
"girl, woman" (especially one of loose morals), 1560s, canting jargon, of unknown origin.
mort (n.2) Look up mort at Dictionary.com
note sounded on a horn at the death of the quarry, c.1500, from French mort "dead," from Latin mortem (source of Spanish muerte, Italian morte), accusative of mors "death" (see mortal (adj.)). Or from French mort "dead," from Vulgar Latin *mortus, from Latin mortuus.