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1. A device consisting of a flat or curved piece (as a metal plate) so that its surface reacts to the water it is passing through
   "the fins of a fish act as hydrofoils";
   - foil
    
2. A speedboat that is equipped with winglike structures that lift it so that it skims the water at high speeds
   "the museum houses a replica of the jet hydrofoil that broke the record";
   - hydroplane

Derived forms: hydrofoils

Type of: device, speedboat

Encyclopedia: Hydrofoil