Английский словарь американских идиом - 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).