Relating to or being deposits, especially near the mouth of a river, formed by the combined action of river and sea.
[Latin fluvius, river; see fluvial + marine.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
1. (Geological Science) (of deposits) formed by joint action of the sea and a river or stream
2. (Zoology) (esp of fish) able to live in both rivers and the sea
[C19: fluvio-, from Latin fluvius river + marine]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014