adjective

belonging to an earlier time.

relics of a bygone age

past,former,earlier,one-time,long-ago,gone by,previous,forgotten,lost,finished,completed,of old,ancient,antiquated,obsolete,departed,dead,extinct,defunct,out of date,outmoded,passé,of yore,olden,foregone,forepassed

noun

a thing dating from an earlier time.

the museum consists of a fascinating collection of rural bygones