The Collaborative International Dictionary of English v.0.48:

Littoral \Lit"to*ral\, a. [L. littoralis, litoralis, from
   littus, litus, the seashore: cf. F. littoral.]
   1. Of or pertaining to a shore, as of the sea.
      [1913 Webster]

   2. (Biol.) Inhabiting the seashore, esp. the zone between
      high-water and low-water mark.
      [1913 Webster]

WordNet (r) 3.0 (2006):

littoral
    adj 1: of or relating to a coastal or shore region
    n 1: the region of the shore of a lake or sea or ocean [syn:
         littoral, litoral, littoral zone, sands]