n. [ Gr. &unr_; wet + -graph. ] (Physics) An instrument for recording automatically the variations of the humidity of the atmosphere. [ 1913 Webster ]
n. One skilled in the hydrography; one who surveys, or draws maps or charts of, the sea, lakes, or other waters, with the adjacent shores; one who describes the sea or other waters. Boyle.
n. [ Hydro-, 1 + -graphy: cf. F. hydrographie. ]