be on

Idioms  

1. Be taking medication or an illegal drug, as in Are you on some antibiotic? or He was definitely on narcotics when it happened . [1930s]

2. Be in favor of something or willing to participate, as in We're going dancing after the play—are you on? [ Colloquial ; late 1800s]

3. Be engaged in some action, especially on the stage, as in Hurry up, you're on in five minutes . [Late 1700s]

4. Perform extremely well, as in I can't return Dan's serve—he's really on today . [ Slang ; second half of 1900s]

5. Be scheduled, as in Is tonight's rally still on? [ Colloquial ; second half of 1990s]

6. be on one . Be at one's expense, either as a treat or the butt of a joke. For example, This round of drinks is on me , or He enjoys a good laugh, even when the joke's on him . [ Colloquial ; second half of 1800s]

7. not be on . Be unacceptable, not allowable, as in I can't believe you'd cancel; that's just not on . This usage is more common in Britain than America. [ Colloquial ; 1930s] For a synonym, see not done . Also see be on to .

8. see be on.

---

Example Sentences

As Boo Radley, a mysterious recluse in “To Kill a Mockingbird,” Duvall was on screen for less than five minutes at the film’s end and had no lines.

From Los Angeles Times

"If I was on the decline I would say it. I'd be the first to say."

From BBC

Stolz, who is listed at 6-foot-1, 180 pounds, would be on the large side for a pro rider, and might have trouble hanging in with the featherweights in the mountains.

From The Wall Street Journal

To vote in person on 7 May, you must be on the electoral register by 23:59 BST on Monday 20 April.

From BBC

You raised them to be independent and critical thinkers so that they can navigate the world, whether they are on the right, the left or some other point on the ideological spectrum.

From MarketWatch

Related Words

• display
• execute
• give
• go on
• offer
• play
• present
• produce
• represent
• show
• stage