look at someone or something with one or both eyes partly closed in an attempt to see more clearly or as a reaction to strong light

the bright sun made them squint

have eyes that look in different directions

Melanie did not squint

a permanent deviation in the direction of the gaze of one eye

I had a bad squint

a quick or casual look

let me have a squint

an oblique opening through a wall in a church permitting a view of the altar from an aisle or side chapel