Literally, vulgar slang for penis, not to be used lightly. More offensive than the schmuck, which can be used affectionately or teasingly. Rarely used to describe the member, schmuck does that.
"What a putz! Used the same as What an asshole!"
(n) a stupid, ignorant person; someone who doesn't pay attention to anything going on; one who makes stupid remarks
"Reiner is a putz. He is always scamming on women. No wonder, he can't stay married."
A "putz" is yiddish (derogatory) for prick.
Oh, don't be such a putz!
Chuck putzes in his office.
Matt putzed on the golf course all day.