flexor

from WordNet (r) 3.0 (2006)

flexor
    n 1: a skeletal muscle whose contraction bends a joint [syn:
         {flexor muscle}, {flexor}] [ant: {extensor}, {extensor
         muscle}]

from The Collaborative International Dictionary of English v.0.48

Flexor \Flex"or\, n. [NL.] (Anat.)
   A muscle which bends or flexes any part; as, the flexors of
   the arm or the hand; -- opposed to {extensor}.
   [1913 Webster] flextime
   flexitime