cover one's tracks
1. To hide and not leave anything, especially foot marks, to show where you have been, so that no one can follow you.
The deer covered his tracks by running in a stream.
To hide or not say where you have been or what you have done; not tell why you do something or what you plan to do.
The boys covered their tracks when they went swimming by saying that they were going for a walk.
Compare: COVER UP (1).