A male given name used as a pejorative name for a man meeting all the negative stereotypes of a Polish middle-aged man, usually pictured with a moustache, a beer belly, wearing socks and sandals. His favorite pastime is watching TV, drinking beer, and complaining about politics and the youth. The closest English equivalent is "boomer".
"Ciągle narzeka na tę dzisiejszą młodzież. To typowy Janusz."
"He's always complaining about kids these days. He's a typical Janusz."