From Longman Dictionary of Contemporary Englishleerleer /lɪə $ lɪr/ verb [intransitive]SMILEto look at someone in an unpleasant way that shows that you think they are sexually attractiveleer atShe was sick of old men leering at her. —leer noun [countable]→ See Verb table
Examples from the Corpus
leer• "Hey, baby. Do you like what you see?" he said, leering.• The man with the goldtoothleered and slapped his hand on her knee.• My boss was a disgusting man who used to leer at me whenever he passed by my desk.• Stopping his work for a second, the garageattendantleered at the girls in the car.• The old man leered suggestively at the waitress.leer at• The man leered at her from the other end of the bar.