tubal
    adj 1: of or relating to occurring in a tube such as e.g. the
           Fallopian tube or Eustachian tube; "tubal ligation";
           "tubal pregnancy"

Tubal \Tub"al\, a.
   Of or pertaining to a tube; specifically, of or pertaining to
   one of the Fallopian tubes; as, tubal pregnancy.
   [1913 Webster]

Tubal
   (1.) The fifth son of Japheth (Gen. 10:2).
   
     (2.) A nation, probably descended from the son of Japheth. It
   is mentioned by Isaiah (66:19), along with Javan, and by Ezekiel
   (27:13), along with Meshech, among the traders with Tyre, also
   among the confederates of Gog (Ezek. 38:2, 3; 39:1), and with
   Meshech among the nations which were to be destroyed (32:26).
   This nation was probably the Tiberini of the Greek historian
   Herodotus, a people of the Asiatic highland west of the Upper
   Euphrates, the southern range of the Caucasus, on the east of
   the Black Sea.
   

Tubal, the earth; the world; confusion