fingerfuck /ˈfɪŋɡɚˌfʌk/noun 1verb 1forms 3 noun1 •(vulgar) The act of sexual penetration or masturbation with the fingers. verb1 •(vulgar) To sexually penetrate or masturbate with fingers.I started to fingerfuck George, which is my favorite sex act — 1990 formsfingerfucked · fingerfucking · fingerfucks