On the possibility that, as in I came early on the chance that we might have time to chat. This phrase uses chance in the sense of “a possibility or probability for some event,” a usage dating from the late 1700s. It is sometimes put as on the off chance, meaning “on the slight but unlikely possibility,” as in I came late on the off chance that I could avoid Thomas. The addition of off in the sense of “remote” dates from the mid-1800s.
- On the defensive
Prepared for withstanding aggression or attack, as in The debate team’s plan was to keep their opponents on the defensive, or This teacher put students on the defensive about their mistakes. [ c. 1600 ]
- On the draw
Related Terms slow on the draw
- On the eve of
Just prior to, as in On the eve of the conference the main speaker backed out. This expression uses eve, literally “the night before,” more loosely. [ Late 1700s ]
- On the fire