The Collaborative International Dictionary of English v.0.48:

Thenal \The"nal\, Thenar \The"nar\, a. [NL., fr. Gr. ?.] (Anat.)
   Of or pertaining to the thenar; corresponding to thenar;
   palmar.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Thenar \The"nar\, n. (Anat.)
   (a) The palm of the hand.
   (b) The prominence of the palm above the base of the thumb;
       the thenar eminence; the ball of the thumb. Sometimes
       applied to the corresponding part of the foot.
       [1913 Webster]

WordNet (r) 3.0 (2006):

thenar
    adj 1: of or relating to the palm of the hand or to the area at
           the base of the thumb [syn: thenal, thenar]
    n 1: the fleshy area of the palm at the base of the thumb
    2: the inner surface of the hand from the wrist to the base of
       the fingers [syn: palm, thenar]