Wordnet 3.0
NOUN (1)
1. 
 a salt or ester of arsenic acid; 
The Collaborative International Dictionary of English v.0.48:
Arsenate \Ar"se*nate\, n. (Chem.)
   A salt of arsenic acid.
   [1913 Webster]
WordNet (r) 3.0 (2006):
arsenate
    n 1: a salt or ester of arsenic acid