noun
masturbation fantasy object; idol used for masturbation
Slang abbreviation of 'onanism idol'. Refers to a person (often a celebrity or fictional character) used as a fantasy object during masturbation. Strongly informal and potentially vulgar.
wasei-eigo (Japanese-coined English), from onanism idol
彼はあのアイドルをオナドルにしているらしい。
Apparently he uses that idol as a masturbation fantasy object.