It has multiple meanings depending on the conversation.

It is another way of saying "OMG, or "Are you for real?", or more commonly used, "Yeah,... right"
Mattie enters Debbies sanctuary and Debbie is alarmed and says loudly, "Your'e back again?! Say swear!"
by SAYSWEARFOOL April 11, 2010
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The weird social phenomenon of adults giving special permission to non-adults (children or teens) to use swear words without social backlash.
Kid: Hey wassup bitches!
Adult: Watch your language kid!
Kid: I have a swear pass.
Adult: Dammit! Blew my chance.
by Chalko3 January 9, 2021
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Expression used when you tell an unbelievable story that is in fact very true.
My little brother is addicted to violent violent games, swear down, I smashed his xbox in front of him.
by Billy-Soo October 7, 2019
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An eternally binding act of hooking middle fingers together in an attempt to seal the deal of a promise that has been made.

If one breaks the rules of the brotherswear, it will result in a swift kick to the testicles.
" YO DAWG THE FIVE-O ARE PARKED OUTSIDE "

" SHEEIT SON, BROTHER SWEAR ? "
by OG-PIMP-HUSTLA April 11, 2010
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An expression used whenever anything happens that is not desired or convienient.
I swear, I'm never staining wood again as long as I live, my hands get SO sticky
by carpentertom May 21, 2006
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an eternally binding promise (made by two people hooking their pinky thumbs together), which, if broken, will result in the culprit losing his or her pinky
"I pinky swore never to cover my mom's garden gnomes with carcinogens....I did and she cut off my pinky with a cleaver."
by Josh Brown May 11, 2005
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