am ‧ phib ‧ i ‧ ous /æmˈfɪbiəs/ BrE AmE adjective
[ Date: 1600-1700 ; Language: Greek ; Origin: amphibios 'living a double life' , from amphi- 'round, on both sides, both' + bios 'way of life' ]
1 . able to live both on land and in water:
amphibious creatures
2 . amphibious vehicle a vehicle that is able to move both on land and in water
3 . amphibious operation/force/assault an amphibious operation etc involves both sea and land vehicles