short for "costume play" a term that comes from the english language and not the from the japaneese language.
Cosplay is a type of performance art whose participants outfit themselves, with often-elaborate costumes and accessories that are commonly called props, to look like as a specific character.
Those Characters are usually sourced in various Japanese and East Asian media, including manga, anime, tokusatsu, comic books, graphic novels, video games, and fantasy movies. Other sources include performers from J-pop, J-rock, Visual Kei, fantasy music stories , novels, and objects from cyberspace or the real world that are unique and dramatic