Here is a list of expressions with once.
Break the fourth wall
To break the fourth wall is to speak directly to your audience during a stage performance.
Cheap at twice the price
If something is cheap at twice the price, it is quite expensive.
- This shop only sells items that are cheap at twice the price.
Don’t think twice
If you don’t think twice about something, you are not concerned about it.
Eleventh hour
If something happens at the eleventh hour, it happens at the last minute.
Even a stopped clock is right twice a day
This expression is used to suggest that a person who don’t usually get things right can be correct on some rare occasions.
Fifth column
This expression is used to refer to people or institutions that support potential invaders while remaining within the country.
Fool me once, shame on you; fool me twice, shame on me
This proverb suggests that if someone cheats you once, the shame is on them, but if you allow them to cheat you twice, the shame is on you. That means you should not trust someone who has cheated you before.
For once
On this particular occasion
- We will forgive him for once.
Fourth estate
An expression used to refer to the press or media. The other three are the clergy, the nobility and the common people.
Lightning never strikes the same place twice
This expression is used to suggest that if something unusual happens in a place, it is unlikely to happen there again.