cover one's tracks

cover one's tracks or cover up one's tracks  {v. phr.}

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.

2.  {informal}

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).