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1. Biology Living or able to live both on land and in water.
2. Able to operate both on land and in water: amphibious tanks.
3. Relating to or organized for a military landing by means of combined naval and land forces.
4. Of a mixed or twofold nature.
[From Latin amphibius, from Greek amphibios; see amphibian.]
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.