Search Result for "a-horizon": 
Wordnet 3.0

NOUN (1)

1. the top layer of a soil profile; usually contains humus;
[syn: A-horizon, A horizon]



WordNet (r) 3.0 (2006):

A-horizon
    n 1: the top layer of a soil profile; usually contains humus
         [syn: A-horizon, A horizon]