Source : Webster's Revised Unabridged Dictionary (1913)

Decumbent \De*cum"bent\, a. [L. decumbens, -entis, p. pr. of
   decumbere; de- + cumbere (only in comp.), cubare to lie
   down.]
   1. Lying down; prostrate; recumbent.

            The decumbent portraiture of a woman. --Ashmole.

   2. (Bot.) Reclining on the ground, as if too weak to stand,
      and tending to rise at the summit or apex; as, a decumbent
      stem. --Gray.

Source : WordNet®

decumbent
     adj : lying down; in a position of comfort or rest [syn: {accumbent},
            {recumbent}, {reclining}]