1797, "hiding place," from French Canadian trappers' slang, "hiding place for stores and provisions" (1660s), a back-formation from French cacher "to hide, conceal" (13c., Old French cachier), from Vulgar Latin *coacticare "store up, collect, compress," frequentative of Latin coactare "constrain," from coactus, past participle of cogere "to collect," literally "to drive together," from com- "together" (see co-) + agere "to set in motion, drive; to do, perform" (from PIE root *ag- "to drive, draw out or forth, move"). Sense extended by 1830s to "anything stored in a hiding place."