1. 
[syn: erstwhile(a), former(a), old, onetime(a), one-time(a), quondam(a), sometime(a)]
WordNet (r) 3.0 (2006):
onetime
    adj 1: belonging to some prior time; "erstwhile friend"; "our
           former glory"; "the once capital of the state"; "her
           quondam lover" [syn: erstwhile(a), former(a), old,
           onetime(a), one-time(a), quondam(a), sometime(a)]
Moby Thesaurus II by Grady Ward, 1.0:
22 Moby Thesaurus words for "onetime":
   ancient, bygone, early, erstwhile, fore, former, immemorial, late,
   old, olden, once, past, prehistoric, previous, primeval, primitive,
   prior, quondam, recent, sometime, then, whilom