1. fellatio as performed by a human being in cosplay attire.
2. the act of putting one's mouth around another's sexual organ (usually a man's), while dressed like a comic book hero, cartoon star, or pretty much anything from anime.
1. conducting oral sex on a male recipient while dressed in cosplay costume.
So I was at DragonCon this year and got a wicked cosjay from Jessica Rabbit. My life is complete.
"I'm going to cosjay your balls off in about a minute. Just let me put on my elf ears."