/huy"droh/ , n. , pl. hydros for 2, 3, adj.
n.
1. Informal. hydroelectric power.
2. Informal. hydroplane.
3. Brit.
a. a bathhouse, hotel, or resort catering to people taking mineral-water health cures; spa.
b. an establishment furnishing hydrotherapy.
adj.
4. Informal. of, pertaining to, or furnishing water, water power, or hydroelectricity: funds for new hydro projects.
[ 1880-85; by shortening of compounds with HYDRO- 1 (cf. -O); (def. 4) HYDRO- 1 analyzed as an adj. ]