noddle
From Longman Dictionary of Contemporary Englishnoddlenod‧dle /ˈnɒdl $ ˈnɑːdl/ noun [countable] British English old-fashioned informal INTELLIGENTyour head or brain It’s easy enough to do if you just use your noddle (=think).Examples from the Corpusnoddle• As for splitting the spoils and building separate, well, you must be off your noddle.