Sleep like a log To sleep very soundly. To sleep very well indeed. The opposite of “sleeping lightly” or having “disturbed sleep”. Related IdiomsMixed idiom: Sleep like a birdMixed idiom: Sleep like a dogMixed idiom: Eat like a logMixed idiom: Sleep like a pig Mixed idiom: Work like a logReal idiom: Sleep like a babyMixed idiom: It sank like a log Post navigationPrevious post: Knock yourself outNext post: Sleep like a baby