1. while busy doing something else.

He eats on the run, grabbing a sandwich in his car.

2. avoiding being found.

A very dangerous man was on the run last night after escaping from prison.

Usage notes: usually refers to avoiding the police

3. at a disadvantage.

The mayor is on the run in this campaign and may even lose the election.

Competition from catalog businesses has department stores on the run.

• come up with
• come up with something
• come what may
• come within an ace of
• come within an ace of doing something
• come within an ace of something
• come within an inch of
• come within an inch of doing something
• come within a whisker of
• come within a whisker of doing something
• come within a whisker of something
• come with the territory
• comings and goings
• commit something to memory
• commit to memory
• commit to memory something
• common ground
• common-or-garden
• common touch
• compare apples and oranges
• compare notes
• conk out
• connect the dots
• contradiction in terms
• contrary to popular belief