hydrau'lic (Gr. n. au'los, a pipe), relating to the motion of water through pipes; worked by water.

hydrau'lics, the science which treats of fluids in motion.

hydroceph'alus (Gr. n. keph'ale, the head), dropsy of the head.

hy'drogen (Gr. v. gen'ein, to beget), a gas which with oxygen produces water.

hydrog'raphy, the art of maritime surveying and mapping.

hydrop'athy (Gr. n. path'os, feeling), the water-cure.

hydropho'bia (Gr. n. phob'os, fear), literally, dread of water; canine madness.

hy'dropsy, a collection of water in the body. ("Dropsy" is a contraction of hydropsy).

hydrostat'ics, the science which treats of fluids at rest.

15. KRAT'OS (χρατος), rule, government, strength.