for one time, on one occasion only; as soon as; when
in the past; occurred one time only
Cases of word usage
1) once more; a second time (again)
2) (a part or mark of) a prehistoric animal or plant once buried in earth, now hardened like rock (fossil)
3) done, happening etc once a month; valid for one month (monthly)
4) the body which moves round the earth once in a month and shines at night (moon)
5) (happening) once in each three months (quarterly)
6) a trace or sign; small remaining bit of what once existed; an organ, or part of one, which is a survival of something that once existed (vestige)
