squint
adj.
1570s, "looking different ways; looking obliquely," shortened form of asquint, adv.. Meaning "looking indirectly" is from 1610s.
v.
1590s, from squint, adj.. Related: Squinted; squinting.
n.
"non-coincidence of the optic axes," 1650s, from squint, adj.. Meaning "sidelong glance" is from 1660s.