I. ˈ ̷ ̷ ̷ ̷+ˌ- noun
Etymology: hydr- + foil
1. : a flat or curved plane surface designed to obtain reaction upon its surfaces from the water through which it moves
ships of all sizes may be effectively stabilized against rolling … by the use of controlled hydrofoils — F.D.Braddon
— compare airfoil , hydroplane
2. : an underwater plate or fin attached by struts to a seaplane (where it is retractable) or to a speedboat for lifting the hull clear of the water as speed is increased
[s]hydrofoi.jpg[/s] [
hydrofoil 2
]
II. noun
: a boat equipped with hydrofoils