This answer seems wrong. I just checked with a native Italian speaker, who said that my answer ("the middle finger") is correct. "The medium" (in the "average" sense) should be "la media".
Il medio has a too many different translations: average, the middle, the middle finger, medium, etc., depending on context.
average = la media the middle = la meta (with an accent on the / a) the middle finger = il dito medio medium = medio the medium = il medio