The Collaborative International Dictionary of English v.0.48:

Adductor \Ad*duc"tor\, n. [L., fr. adducere.] (Anat.)
   A muscle which draws a limb or part of the body toward the
   middle line of the body, or closes extended parts of the
   body; -- opposed to abductor; as, the adductor of the eye,
   which turns the eye toward the nose.
   [1913 Webster]

         In the bivalve shells, the muscles which close the
         values of the shell are called adductor muscles.
                                                  --Verrill.
   [1913 Webster]

WordNet (r) 3.0 (2006):

adductor
    n 1: a muscle that draws a body part toward the median line
         [syn: adductor, adductor muscle]