be on the lookout


Also found in: Acronyms.

be on the lookout

Watching for something or someone. Be on the lookout for my e-mail! It will have all the instructions you need for the project. A: "What are you guys doing?" B: "We're on the lookout for mom's car, so we can tell dad to stop working on her surprise gift when she gets here."
See also: lookout, on