Adjective once has 1 sense
- erstwhile, former, once, onetime, quondam, sometime - belonging to some prior time; "erstwhile friend"; "our former glory"; "the once capital of the state"; "her quondam lover"
Antonym: present (indirect, via future, past)
Antonym: future (indirect, via past, present)
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Adverbial once has 3 senses
- once, one time, in one case - on one occasion; "once I ran into her"
- once, when - as soon as; "once we are home, we can rest"
- once, formerly, at one time, erstwhile, erst - at a previous time; "once he loved her"; "her erstwhile writing"
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