to close and open the eyes involuntarily
(often + at) to look at something with half-shut eyes
to shine intermittently
(+ at) to condone or ignore a wrongdoing, injustice, etc
(+ at) to look with surprise or dismay at something
to cause (one's eyes) to blink
(+ away/back) to remove or stop (something) by blinking
He blinked back his tears
to condone or ignore (something)
[Middle English blinken to open one's eyes, from blenk, Scots variant of blench]