adjective
- gone; gone by; past (usually preceded by a noun): five days ago.
adverb
- in past time; in the past: All this happened long ago.
adverb
- in the pastfive years ago; long ago
early 14c., shortened form of Old English agan, agone “departed, passed away,” past participle of an obsolete verb ago “to go forth,” formed from a- “away” (perhaps here used as an intensive prefix) + gan “go” (see go (v.)). Agone remains a dialectal variant.