Once synonyms such as at a time, a single time, and a while ago. Once is an adverb, and its antonyms are twice and many times. Additionally, here are 31 synonyms and nearby words for once as well as words beginning with O, On, Onc, and Once.
31 synonyms for once
A single time
A while ago
At a time
At an earlier time
At one point
At one time
At some point
Back in the day
Back then
Before now
Earlier
Erstwhile
Former
Formerly
Historically
In bygone days
In days gone by
In earlier days
In former times
In history
In previous years
In the old days
In the past
Long ago
Long since
On one occasion
Once upon a time
One time
Sometime