(frequency) One and only one time.
‘I have only once eaten pizza.’;
(sports) A senior or first team (as opposed to a reserves team).
(temporal location) Formerly; during some period in the past.
‘He was once the most handsome man around.’; ‘I once had a bicycle just like that one.’;
(mathematics) Multiplied by one: indicating that a number is multiplied by one.
‘Once three is three.’;
As soon as.
(obsolete) At a future time.
‘If the facts once became known, we'd be in trouble.’;
As soon as; when; after.
‘We'll get a move on once we find the damn car keys!’; ‘Once you have obtained the elven bow, return to the troll bridge and trade it for the sleeping potion.’; ‘Once he is married, he will be able to claim the inheritance.’;
For one time; by limitation to the number one; not twice nor any number of times more than one.
‘Ye shall . . . go round about the city once.’; ‘Trees that bear mast are fruitful but once in two years.’;
At some one period of time; - used indefinitely.
‘My soul had once some foolish fondness for thee.’; ‘That court which we shall once govern.’;
At any one time; - often nearly equivalent to ever, if ever, or whenever; as, once kindled, it may not be quenched.
‘Wilt thou not be made clean? When shall it once be?’; ‘To be once in doubtIs once to be resolved.’;
belonging to some prior time;
‘erstwhile friend’; ‘our former glory’; ‘the once capital of the state’; ‘her quondam lover’;
on one occasion;
‘once I ran into her’;
as soon as;
‘once we are home, we can rest’;
at a previous time;
‘once he loved her’; ‘her erstwhile writing’;