Source : Webster's Revised Unabridged Dictionary (1913)

Senhor \Se*nhor"\, n. [Pg. Cf. {Se[~n]or}, {Senior}.]
   A Portuguese title of courtesy corresponding to the Spanish
   se[~n]or or the English Mr. or sir; also, a gentleman.

Source : WordNet®

Senhor
     n : a Portuguese title of respect; equivalent to English `Mr'