(1) (Chem) An intimate mixture of particles and a fluid, such as smoke or fog in the air, in which the particles are dispersed but not dissolved. Note: Suspensions usually consist of particles larger than colloidal size (>0. 2 micron) and tend to settle unless the fluid is in motion. Emulsions, by contrast, are liquid suspensions of liquid particles of colloidal dimensions and are stable for long periods. A gel is a suspension of a solid in a liquid phase. Foam is a colloid in which a continuous liquid medium surrounds gas bubbles. The film is so thin as to be colloidal, while the enclosed bubble may be either colloidal or macroscopic. A sol is a suspension of a solid in a liquid phase. (2) (Mech Eng) a. A device by which something is suspended, such as a gimbal. b. A body that is suspended, such as a bridge. (3) (Fire Pr) Relief from duty, generally as a punishment or during the period of an investigation of alleged misconduct