Wink
The wink is an intentional facial expression made by closing one eye; it is distinguished from the blink by the fact that the other eye remains open. A wink is a form of semi-formal communication, which indicates shared, unspoken knowledge. In simple words, if a male winks at you with a smile, he may be interested in you and want to start a conversation or more.
A "naughty wink" can silently indicate a shared secret, such as if a salesperson gives a customer a brochure and says, "Here you go, it's free". Infrequently, it may also mean "got it" or "yes, I understand".
In Western cultures, women may wink to men they are interested in dating, but this has grown out of fashion, though still used occasionally. Winking is also done by men to women.
In Latin American cultures, winking is also a romantic or sexual invitation. [1]
In Nigeria, winking is a signal for children to leave the room. [2] Many Chinese consider winking to be rude. [3].
Not all humans are able to wink voluntarily, and some can only wink one (usually the non-dominant) eye but not the other.