Definitions of leer:

• noun:   a suggestive or sneering look or grin
• noun:   a facial expression of contempt or scorn; the upper lip curls
• verb:   look suggestively or obliquely; look or gaze with a sly, immodest, or malign expression

  Example: "The men leered at the young women on the beach"

• name:  A surname (very rare: popularity rank in the U.S.: #25398)