onetime

1 happening only once with any luck, that was a onetime mistake Synonyms one-off, one-shot Related Words nonce; inconstant, infrequent, intermittent, irregular, occasional Near Antonyms common, commonplace, everyday, familiar, ordinary, routine, ubiquitous, usual; cyclic (or cyclical); around-the-clock, constant, continual, hourly, round-the-clock; accustomed, chronic, confirmed, customary, habitual, inveterate; expected; annual, yearly Antonyms frequent, periodic, periodical, recurrent, recurring, regular, repeated, steady

2 having been such at some previous time the onetime English teacher now works for a newspaper Synonyms erstwhile, late, old, once, former, other, past, quondam, sometime, whilomRelated Words bygone, dead, defunct, departed, expired, extinct, gone, long-ago, vanishedNear Antonyms contemporary, current, extant, ongoing, present, present-day; coming, future, prospective, unborn