Meanings
Germany · Western · colloquial · regionaltomfool, a male person who is (for whatever reason) ridiculous, not to be taken seriously
Der Typ ist so ein Tünnes!The guy is such a tomfool!
Germany · Western · colloquial · regionala male person who is clumsy or forgetful (less negative than sense 1)
Och du Tünnes, du solltest doch Butter mitbringen!Hey stupid, you were supposed to bring butter, too!