living or able to live both on land and in water; belonging to both land and water.
2.
Also, amphibian.capable of operating on both land and water: amphibious vehicles.
3.
of or pertaining to military operations by both land and naval forces against the same object, especially to a military attack by troops landed by naval ships.
4.
trained or organized to fight, or fighting, on both land and sea: amphibious troops.
5.
combining two qualities, kinds, traits, etc.; of or having a mixed or twofold nature.
Origin: 1635–45; < Latin amphibius < Greek amphíbios living a double life. See amphi-, bio-, -ous