One time.
One and the same time: usually with at: as, they all cried out at once. See phrases below.
At one time in the past; formerly.
At some future time; some time or other.
At any time; in any contingency; on any occasion; under any circumstances; ever.
Without delay; immediately: often merely expletive: as, John, come here once.
Once for all.
Immediately; forthwith; without delay.
When at any time; whenever; as soon as.
noun.
An obsolete form of ounce.