Definition
An aircraft equipped with landing gear that allows it to take off and land on either water or a hard surface runway. Amphibians typically have a boat-like hull or floats for water operations, combined with retractable wheels for use on land.
Plain English
A plane that can land and take off from both water and a regular runway, because it has both floats or a boat-shaped bottom and wheels that fold down when needed.
Context Anchor
Seen in aircraft type descriptions, operating limitations, training materials, and preflight planning for flights involving lakes, rivers, seaplane bases, or land airports.
Derivation
From the Greek 'amphibios' meaning 'living a double life' -- 'amphi' (both) and 'bios' (life). The word originally described animals like frogs that live both in water and on land. An amphibian aircraft has the same double-life quality: it can operate in two different environments.
Why Pilots Care
Allows operations in remote areas without runways, expanding access for transport, training, and recreation.
Intuition Check
Do not read “amphibian” here as an animal category. In aviation, it means the aircraft can use both water and land for takeoff and landing.
Example Sentence 1
The pilot flew the amphibian aircraft from the lake in the morning and landed at the paved airport that afternoon.
Example Sentence 2
Training for an amphibian aircraft includes both water taxiing and runway takeoffs.