rot meaning, definition, what is rot: to (cause something to) decay. Learn more. Stop the rot idiom · English · Français · Dry rot. Meaning, pronunciation, example sentences, and more from Oxford Dictionaries. with object 'caries sets in at a weak point and spreads to rot the whole tooth'. Define rot: to slowly decay or cause (something) to decay — rot in a sentence. Examples from the Web for rot Expand. Times, Sunday Times Will the rescue stop the rot in the eurozone? What does gorge mean? Neither the timber frame nor metal chassis were protected against rot. Select category from list Revised Organized Throb Community. Again, this proposition of cutting down drinks to two or three a day is all rot.