Pertaining to small penises; Derived from the well known fact that all Europeans have miniscule genitalia.
Jenny: Girl, that guy last night was terrible.
Tiffany: Yeah, he was Eurosized.
Jenny: Yeah, his penis was the smallest thing ive ever seen!
Tiffany: No kidding girl, it was like spaghetti, but it wasn't even long!
Jenny: Yeah, im totally gonna play for the other team next time.
Tiffany: Damn Eurosize.