Defn: Of a boat, to plane (see Plane, below).
HYDROPNEUMATIC Hy`dro*pneu*mat"ic, a. Etym: [Hydro-, 1 + pneumatic: cf. F. hydropneumatique.]
Defn: Pertaining to, or depending upon, both liquid and gaseous substances; as, hydropneumatic apparatus for collecting gases over water or other liquids.
HYDROPNEUMATIC GUN CARRIAGE
Hy`dro*pneu*mat"ic gun carriage. (Ordnance)
Defn: A disappearing gun carriage in which the recoil is checked by cylinders containing liquid and air, the air when compressed furnishing the power for restoring the gun to the firing position. It is used with some English and European heavy guns.
HYDROPSY
Hy"drop`sy, n.
Defn: Same as Dropsy.
HYDROPULT
Hy"dro*pult, n. Etym: [Hydro-, 1 + Gr.
Defn: A machine for throwing water by hand power, as a garden engine, a fire extinguisher, etc.
HYDROQUINONE
Hy`dro*qui"none, n. Etym: [Hydro-, 2 + quinone.] (Chem.)