socket n.

c. 1300, soket, "spearhead" (originally one shaped like a plowshare), from Anglo-French soket "spearhead, plowshare" (mid-13c.), diminutive of Old French soc "plowshare," from Vulgar Latin *soccus, which is perhaps from Gaulish, from Celtic *sukko- (source also of Welsh swch "plowshare," Middle Irish soc "plowshare"), properly "hog's snout," from PIE *su- "pig" (source also of Latin sus "swine;" see sow (n.)).

The meaning "hollow part or piece for receiving and holding something," especially a candle, is recorded from early 15c.; the anatomical sense of "hollow of one part which receives another" is from c. 1600. The domestic electrical outlet sense is recorded by 1885.

Socket wrench is attested from 1837. Socket-pipe is by 1858. The verb, "provide with or place in a socket," is by 1530s, from the noun. Related: Socketed; socketing.