Fig.: man who harasses a woman on the street making unwanted crude or sexual comments

That man made cat calls and followed me the entire time, until he finally realized it would be better to leave me alone

Quel pappagallo mi ha seguito per tutta la strada, quando finalmente ha capito che era meglio lasciarmi stare 

Italy: Policing the "Pappagalli."
Known locally as “pappagalli” (parrots) for their incessant and provocative chatter (“Eh, bella, you speaka English? Wanna spaghetti?), as well as for their pinching and poking. (Time Magazine - Aug. 16, 1968)

Italia: il controllo dei "Pappagalli".
Conosciuti localmente come “pappagalli” per il loro chiacchiericcio incessante e provocatorio (“Eh, bella, parli inglese? Ti vanno gli spaghetti?”), oltre che per i loro pizzicotti e le loro spinte. (Time Magazine - 16 agosto 1968)

Originally (1600s) the "catcall" was a real whistle that made a harsh noise similar to a crying cat, used by theatergoers to boo a bad performance.
Later on, this term referred to audiences' actual sound of disapproval, including hissing and whistling. Nowadays, theaters are not involved any more, but it refers to someone who targets a woman on the street with unwelcome whistles, honks, or vulgar comments.