The Collaborative International Dictionary of English v.0.48:

Cyanuric acid \Cyanuric acid\ (Chem.),
   an organic acid, C3O3N3H3, first obtained by heating uric
   acid or urea, and called pyrouric acid; afterwards obtained
   from isocyanic acid. It is a white crystalline substance,
   odorless and almost tasteless; -- called also tricarbimide.
   [1913 Webster]

WordNet (r) 3.0 (2006):

cyanuric acid
    n 1: a trimer of cyanic acid