Another word for once
this time, but once, once only, one time before, already, one, just this once, for the nonce, not more than once, never again, a single time, one time previously, on one occasion, only one time.
Antonyms twice*, many times, frequently.
for at least one time, once only, uniquely; see once 1.
Another word for onceadverb
At a time in the past:already, before, earlier, erstwhile, formerly, previously. (Archaic) aforetime, beforetime. See precede