mutunium

Etymology
Probably from ; compare (used with a sexual sense in Plautus and Petronius). The derived adjective scans with a short first syllable; Weiss (1996) proposes that this is a case of a geminate being shortened after an unaccented vowel, as seen in  for  (compare  from ). It is not known why the vowel in the second syllable appears as ū rather than as ō. (The spelling is attested in Lucilius.) Weiss proposes the following origin for forms with ū in this family of words: initially, the root was combined with the suffix, forming an adjective. After becoming used as the name of a god, Mutunus Tutunus, the form was altered to  under the influence of other deity names ending in, such as  and , and then the ū in the second syllable of  served as the basis of ū in the second syllable of forms like  and.

Noun

 * 1)  penis