The Collaborative International Dictionary of English v.0.48:

Scree \Scree\ (skr[=e]), n.
   A pebble; a stone; also, a heap of stones or rocky d['e]bris.
   [Prov. Eng.] --Southey.
   [1913 Webster]

WordNet (r) 3.0 (2006):

scree
    n 1: a sloping mass of loose rocks at the base of a cliff [syn:
         talus, scree]