First attested in the Beonyeok nogeoldae (飜譯老乞大 / 번역노걸대), 1517, as 도ᇰ모(Yale: twongmwo). May be ultimately of Sino-Korean origin, from 동모 (同謀, dongmo, “planning together; complotting; collusion”). Alternatively, it could be of native origin and influenced by 동 (同, dong, “together”); compare Japanese友(tomo, “friend, pal”).