cos·play 
(kŏzplā′)
(kŏzplā′)n.
The act or practice of dressing in costume, often homemade, to resemble or portray a fictional character, especially from science fiction, fantasy, manga, or anime.
v. cos·played, cos·play·ing, cos·plays
v.intr.
To engage in cosplay.
v.tr.
To portray (a character) through cosplay: She cosplayed her favorite superhero at a comic book convention.
[COS(TUME) + PLAY.]
cosplay·er n.