The Collaborative International Dictionary of English v.0.48:

Briarean \Bri*a"re*an\, a. [L. Briareius, fr. Briareus a
   mythological hundred-handed giant, Gr. ?, fr. ? strong.]
   Pertaining to, or resembling, Briareus, a giant fabled to
   have a hundred hands; hence, hundred-handed or many-handed.
   [1913 Webster]