• (n.) A contrivance or apparatus to prevent the explosion of steam boilers. • (n.) A device, usually electrical, for indicating or regulating the height of water in a reservoir or receptacle.
A device for regulating water level. ... Origin: hydro-+ G. Statikos, causing to stand ... (05 Mar 2000) ... 
Lowe Alpine's waterproof/breathable fabric made from coated ripstop polyester. More waterproof than it is breathable.
Hy'dro·stat noun A contrivance or apparatus to prevent the explosion of steam boilers. 
Type: Term Pronunciation: hī′drō-stat Definitions: 1. A device for regulating water level. 2. any organism or organ with a shape that is maintained by internal fluid pressure against the sheath (tongue, penis).
hydrostat, hydrostatic A device designed to regulate the height of fluid in a column, reservoir, or other container.
an electrical device for detecting the presence of water, as from overflow or leakage. · any of various devices for preventing injury to a steam boiler when its water sinks below a certain level.