“This became increasingly set up in America after which, in 1984, magazine creator Nobuyuki Takahashi located the trend even as at Los Angeles's World Science Fiction Convention.  Cosplay Costume
 

He turned into struggling for a word to explain it to his Japanese audience. He settled on cosplay, written in katakana as コスプレ, a portmanteau of the English words 'gown' and 'play' with a purpose to describe the mixture of dressing up and acting the component.” Wanda Maximoff Costume