The Collaborative International Dictionary of English v.0.48:

Anticlinal \An`ti*cli"nal\, n. (Geol.)
   The crest or line in which strata slope or dip in opposite
   directions.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Anticlinal \An`ti*cli"nal\ ([a^]n`t[i^]*kl[imac]"nal), a. [Pref.
   anti- + Gr. kli`nein to incline.]
   1. Inclining or dipping in opposite directions. See
      Synclinal.
      [1913 Webster]

   2. (Bot.) occurring at right angles to the surface of a plant
      organ.
      [PJC]

   Anticlinal line, Anticlinal axis (Geol.), a line from
      which strata dip in opposite directions, as from the ridge
      of a roof.

   Anticlinal vertebra (Anat.), one of the dorsal vertebr[ae],
      which in many animals has an upright spine toward which
      the spines of the neighboring vertebr[ae] are inclined.
      [1913 Webster]

WordNet (r) 3.0 (2006):

anticlinal
    adj 1: sloping downward away from a common crest [ant:
           synclinal]