The Collaborative International Dictionary of English v.0.48:

Segmental \Seg*men"tal\, a.
   1. Relating to, or being, a segment.
      [1913 Webster]

   2. (Anat. & Zool.)
      (a) Of or pertaining to the segments of animals; as, a
          segmental duct; segmental papillae.
      (b) Of or pertaining to the segmental organs.
          [1913 Webster]

   Segmental duct (Anat.), the primitive duct of the embryonic
      excretory organs which gives rise to the Wolffian duct and
      ureter; the pronephric duct.

   Segmental organs.
      (a) (Anat.) The embryonic excretory organs of vertebrates,
          consisting primarily of the segmental tubes and
          segmental ducts.
      (b) (Zool.) The tubular excretory organs, a pair of which
          often occur in each of several segments in annelids.
          They serve as renal organs, and often, also, as
          oviducts and sperm ducts. See Illust. under
          Sipunculacea.

   Segmental tubes (Anat.), the tubes which primarily open
      into the segmental duct, some of which become the urinary
      tubules of the adult.
      [1913 Webster]

WordNet (r) 3.0 (2006):

segmental
    adj 1: divided or organized into speech segments or isolable
           speech sounds
    2: having the body divided into successive metameres or
       segments, as in earthworms or lobsters [syn: metameric,
       segmental, segmented]