To whistle or yell
something sexually suggestive to a
stranger, usually in passing. Often this is used by sexually frustrated males as a
way of getting attention from females. It is not a recommended method of flattering someone.
"I was minding my own business at a bus stop when some
creep shouted 'nice rack' out of his
car window at me."
"Eeew, I hate cat calls. I'm so
sorry someone made you feel uncomfortable like that."