hydroplane

UK: /ˈhaɪdrəpleɪn/ US: /ˈhaɪdrəˌpleɪn/ ,(hī′drə plān′)

Inflections of 'hydroplane' (v): (⇒ conjugate)

hydroplanes

v 3rd person singular

hydroplaning

v pres p

hydroplaned

v past

hydroplaned

v past p

WordReference Random House Learner's Dictionary of American English © 2026

hy•dro•plane /ˈhaɪdrəˌpleɪn/   n., v., -planed, -plan•ing. 
n. [countable]

1. Aeronautics a seaplane.
2. Nautical, Naval Terms a light, high-powered boat designed to skim along the surface of the water at high speeds.

v. [no object]

3. Naval Terms to skim over water in the manner of a hydroplane.
4. Naval Terms to travel in or pilot a hydroplane.

See -hydr-.

WordReference Random House Unabridged Dictionary of American English © 2026

hy•dro•plane  (hī′drə plān′), n., v., -planed, -plan•ing. 
n. 

1. Aeronautics a seaplane.
2. Aeronautics an attachment to an airplane enabling it to glide on the water.
3. Nautical, Naval Terms a light, high-powered boat, esp. one with hydrofoils or a stepped bottom, designed to plane along the surface of the water at very high speeds.
4. Nautical, Naval Terms a horizontal rudder for submerging or elevating a submarine.

v.i. 

5. Aeronautics, Naval Terms to skim over water in the manner of a hydroplane.
6. Aeronautics, Naval Terms to travel in a hydroplane.
7. Automotive Also, aquaplane. (of a vehicular tire or vehicle) to ride on a film of water on a wet surface with a resulting decrease in braking and steering effectiveness.

• hydro-¹ + plane¹ 1900–05

Collins Concise English Dictionary © HarperCollins Publishers::

hydroplane / ˈhaɪdrəʊˌpleɪn/ noun

1. a motorboat equipped with hydrofoils or with a shaped bottom that raises its hull out of the water at high speeds
2. an attachment to an aircraft to enable it to glide along the surface of water
3. another name (esp US) for a seaplane
4. a horizontal vane on the hull of a submarine for controlling its vertical motion

verb

1. (intransitive) (of a boat) to rise out of the water in the manner of a hydroplane