have on
phrasal verbhave somebody on 
- (informal) to try to make somebody believe something that is not true, usually as a joke
- You didn't really, did you? You're not having me on, are you?
 
 
have (got) something on [no passive] not used in the progressive tenses
- to be wearing something
- She had a red jacket on.
 - He had nothing (= no clothes) on.
 
 - to leave a piece of equipment working
- She has her TV on all day.
 
 - to have arranged to do something
- I can't see you this week—I've got a lot on.
 
 
have (got) something on somebody 
- [no passive] (informal) (not used in the progressive tenses) to know something bad about somebody, especially something that connects them with a crime
- I'm not worried—they've got nothing on me.