1 C1 idiomatic slang
(British slang) To be in a state of extreme excitement or high energy, often due to alcohol, drugs, or sheer enthusiasm.
"She was absolutely on one last night — dancing until four in the morning."
inseparable
be on one
C1 slang inseparable intransitive
British slang: to be in a highly energised, excited, or intoxicated state, often at a party or after taking drugs.
In plain English
To be acting very wild, excited, or like you've had too much to drink or taken something.
What does "be on one" mean?
One main meaning — here's how to use it.
Usage tip
Very British, very informal. Commonly heard in club or party settings. Can refer to alcohol or drug intoxication, or simply to someone being in a very excitable mood. Not appropriate in formal contexts.
Words that pair with "be on one"
Natural word combinations native speakers use most often.
night out party dancing completely absolutely totally
How to conjugate "be on one"
The five tense forms you'll use most often.
Base
be on one
I/you/we/they
3rd person
is on one
he/she/it
Past simple
was/were on one
yesterday
Past participle
been on one
have + pp
-ing form
being on one
continuous
Hear "be on one" in the wild
Listen to native speakers using "be on one" in real YouTube videos — click a clip to watch it on Looplines.
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