Cosplay Definition Meaning Explain costume play in simple terms. Costume play refers to dressing up and pretending to be a specific character from a anime. This trend has become immensely popular among enthusiasts of geek culture internationally. Individuals diligently design outfits and accessories in order to faithfully represent their favorite characters. Cosplayers usually participate in events or costume play events, where they can showcase their artistry and network with others who share the same passion. Ultimately, costume play is an form of admiration and dedication for the fictional character and a love for the geek community.