Source : Webster's Revised Unabridged Dictionary (1913)

Vena \Ve"na\, n.; pl. {Ven[ae]}. [L. See {Vein}.]
   A vein.

   {Vena cava}; pl. {Ven[ae] cav[ae]}. [L., literally, hollow
      vein.] (Anat.) Any one of the great systemic veins
      connected directly with the heart.

   {Vena contracta}. [L., literally, contracted vein.]
      (Hydraulics) The contracted portion of a liquid jet at and
      near the orifice from which it issues.

   {Vena port[ae]}; pl. {Ven[AE] port[ae]}. [L., literally, vein
      of the entrance.] (Anat.) The portal vein of the liver.
      See under {Portal}.

Source : WordNet®

vena
     n : a blood vessel that carries blood from the capillaries
         toward the heart; all veins except the pulmonary carry
         unaerated blood [syn: {vein}, {venous blood vessel}]
     [also: {venae} (pl)]