Source : Webster's Revised Unabridged Dictionary (1913)

Tubal \Tub"al\, a.
   Of or pertaining to a tube; specifically, of or pertaining to
   one of the Fallopian tubes; as, tubal pregnancy.

Source : WordNet®

tubal
     adj : of or relating to occurring in a tube such as e.g. the
           fallopian tube or eustachian tube; "tubal ligation";
           "tubal pregnancy"