Old English hamor "hammer," from Proto-Germanic *hamaraz (cognates: Old Saxon hamur, Middle Dutch, Dutch hamer, Old High German hamar, German Hammer). The Old Norse cognate hamarr meant "stone, crag" (it's common in English place names), and suggests an original sense of the Germanic words as "tool with a stone head," from PIE *akmen "stone, sharp stone used as a tool" (cognates: Old Church Slavonic kamy, Russian kameni "stone"), from root *ak- "sharp" (see acme). Hammer and sickle as an emblem of Soviet communism attested from 1921, symbolizing industrial and agricultural labor.

late 14c., from hammer, n.. Meaning "to work (something) out laboriously" recorded from 1580s. Meaning "to defeat heavily" is from 1948. Related: Hammered; hammering. Hammered as a slang synonym for "drunk" attested by 1986.