a homosexual person or action that is so openly gay and disgusting, it's both gay and nasty.
Two guys kissing each other at the bar in public would be deemed fagnasty.

or used in context:

Joe: "You see that 300 lb fag wearing a thong over there holding hands with that other dude?"

Jeff: "Yeah that's totally fagnasty!"

Fagnasty can also be used as an insult for extra emphasis:

"Get the fuck out of my way you fagnasty faggot!"
by JHop February 14, 2008
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fagnasty-someone who is a fag and is really mean
Bubba Sink is fagnasty.
by Brittany1104 June 21, 2007
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When a person of a homosexual orientation gives you the creeps or freaks you out, most often by making some kind of sexuual advance or flirtatious gesture thus making you feel uncomfortable.
R:Hey did you see that guy looking at my ass?
T:Yeah I did.........
R:He totally gave me the Fagnasties
by RVL November 7, 2007
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