When someone has taken ecstacy and they clench their teeth and their jaw hangs and looks like it is out of joint.
"Check the eccie jaw on that it's swinging"

"Too much swej!"
by Cheese123willz November 9, 2013
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When your jaw goes all ways after taking ecstasy.
Vicky Pattison has an eccy jaw
by Smithtin December 2, 2015
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