The Collaborative International Dictionary of English v.0.48:

Pluvious \Plu"vi*ous\, a. [L. pluviosus, pluvius, fr. pluvia
   rain: cf. F. pluvieux. See Pluvial, a.]
   Abounding in rain; rainy; pluvial. --Sir T. Browne.
   [1913 Webster]