From Longman Dictionary of Contemporary Englishclean sheet/slateclean sheet/slateMISTAKEa record of someone’s work, behaviour, performance etc that shows they have not done anything wrong or made any mistakes Jed looked forward to starting life again with a clean sheet. Lewis has kept a clean sheet in every game (=not let the other team score). → clean
Examples from the Corpusclean sheet/slate• When things go wrong Many people today believe that children begin life with a clean slate.• He wanted to use the subsidiary as a totally clean slate and he wanted true collaboration from the beginning.• Hereford just can't keep a clean sheet and their lowly league position reflects that.• Everton's record of failing to keep a clean sheet in 15 matches soon looked ominously likely to continue.• A clean sheet of blotting paper should be in the blotter. 5.• Orson Pratt, one of the originals, stressed the clean slate of history on which they wrote.• They are treading unfamiliar ground in the relegation zone and have failed to keep a clean sheet this season.• The new-born child is virtually a clean slate, to be written on by the world.