Meaning

noun a bony hollow into which a structure fits

noun receptacle where something (a pipe or probe or end of a bone) is inserted

noun a receptacle into which an electric device can be inserted

originFrom Middle English socket, soket, from Anglo-Norman soket (“spearhead”), diminutive of Old French soc (“plowshare”), from Vulgar Latin *soccus, a word borrowed from Gaulish, from Proto-Celtic *sukkos (compare modern Welsh swch (“plowshare”)), literally "pig's snout", from Proto-Indo-European *suH-.

Etymology from Wiktionary, CC BY-SA 3.0