erstwhile

adjectives

belonging to some prior time
"erstwhile friend"; "our former glory"; "the once capital of the state"; "her quondam lover"
erstwhile, former, old, one-time, onetime, quondam, sometime

adverbs

at a previous time
"at one time he loved her"; "her erstwhile writing"; "she was a dancer once";
at one time, erst, erstwhile, formerly, once