The hairy eyeball
A glance made with partially lowered eyelashes. This usually indicates suspicion or hostility but may signal other emotions too.
This is a US phrase from the 1960s and is largely restricted to US use. The earliest known printed record of it is from The Galveston Daily News, November 1961, in a piece that reports on an interview with Carol Burnett:
'With her [Burnett's sister] everything is boys-boys-boys. She's really educated me. She was telling me about a boy looking at her and she said, "He gave me the hairy eyeball." That meant he liked her.'
That appears to contradict the usual suspicious and hostile meaning which is evident in this slightly later piece from The New York Times, November 1963:
"He gave me the hairy eyeball" - means that someone is disapproving.