What's keeping?
What's keeping someone?
What is delaying someone? (The someone is replaced by a person's name or a pronoun.) Bob: Wasn't Mary supposed to be here? Bill: I thought so. Bob: Well, what's keeping her? Bill: How should I know? Bill: I've been waiting here for an hour for Sally. Sue: What's keeping her?
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
- can't fight City Hall, one/you/they
- We were just talking about you
- on (one's) bill
- fill the bill
- fill the bill, to
- pick up the bill
- greenback
- foot the bill
- meet one's Waterloo, to
- fit the bill