<p><strong>Noun</strong></p><ul><li>A seaplane.</li><li>An attachment to an airplane enabling it to glide on the water.</li><li>A light, high-powered boat, especially one with hydrofoils or a stepped bottom, designed to plane along the surface of the water at very high speeds.</li><li>A horizontal rudder for submerging or elevating a submarine.</li></ul><p><strong>Verb</strong></p><ul><li>(Used without object) hydroplaned, hydroplaning.<ul><li>To skim over water in the manner of a hydroplane.</li><li>To travel in a hydroplane.</li><li>Also (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.</li></ul></li></ul>