From Longman Dictionary of Contemporary Englishgive it a restgive it a restspoken especially British EnglishQUIET used to tell someone to stop talking about something because they are annoying you Give it a rest, Jack! → rest
Examples from the Corpus
give it a rest• Take your head off and give it a rest.• I think you should just give it a rest for a few weeks.• You've been complaining all day. Why don't you just give it a rest?• It is not only more kind, but more intelligent, to give it a rest or let it slow down.• There was a reason for stopping, at least a reason to give it a rest.• It was time to give it a rest. 