The Collaborative International Dictionary of English v.0.48:
Fluvial \Flu"vi*al\, a. [L. fluvialis, from fluvius river, fr. fluere to flow: cf.F. fluvial. See Fluent.] Belonging to rivers; growing or living in streams or ponds; as, a fluvial plant. [1913 Webster]WordNet (r) 3.0 (2006):
fluvial adj 1: of or relating to or happening in a river; "fluvial deposits"