A buttwink is when a person flexes their anal sphincter, causing their anus to visibly contract, effectively "winking" with their asshole. Buttwinking can be performed as an obscene gesture, or in a sexual context it can be either a sign of affection or a greeting.

To buttwink, simply use the same muscles used to defecate to flex your anus.

This act should not be confused with mooning (merely exposing your anus) since buttwinking is considerably more rude.
As Sensei Doug walked to his dojo, the rude employees of a strip mall store lowered their drawers, pointed their behinds towards the window, and contracted their assholes to buttwink at the passing martial artist.
by Sensei Doug December 6, 2017
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When your "brown eye" (also known as an anus hole) contracts, which causes a closing effct. Once the anus hole opens once more its ends the completion of the "buttwink".

Buttwinks often occur when pinching off a turd while taking a dump or during sexual intercourse (when climaxing for both sexes).
I had to buttwink to pinch off that turd

Dude!, I was having sex with this hot chick last night and she buttwinked when she orgasmed, thats when I decided to try anal.
by Blackrose86 January 19, 2011
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The feeling that occurs immediatly following an extra large shit, when your butthole contracts as a result of the 2x4 that was just pushed through your 0-ring.
Man, you should have seen that turd. My butthole is still winking ;0
by Long-log-man December 22, 2004
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some crappy word from balderdash, for which i cannot remember the correct definition.
define buttwink, please.
by andrea December 19, 2004
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When there is a wiener on your butt also known as your anal hole and the male misses your butthole by trying to insert it in your butt.
OMG hes totally a buttwinker , he missed so bad
by Madisyon banks February 20, 2017
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