Adjectives

(s)erstwhile, former, old, onetime, one-time, quondam, sometimebelonging to some prior time“erstwhile friend”, “our former glory”, “the once capital of the state”, “her quondam lover”

Adverbs

(r)once, formerly, at one time, erstwhile, erstat a previous time“at one time he loved her”, “her erstwhile writing”, “she was a dancer once”