Fire retardant that inhibits combustion primarily by the cooling and smothering action of water. Chemicals may be added to the water to alter its viscosity or retard its evaporation, thereby increasing its effectiveness.

The area on the ground covered by the combined aerial parts of plants expressed as a percent of the total area.

Air which has assumed high moisture content and the temperature characteristics of a water surface due to extensive exposure to that surface.

The incident commander at the time the first attack forces commence suppression work on a fire.

An externally threaded hose nipple which fits in the thread of a female (internally threaded) swivel coupling of the same pitch and diameter. Nozzles attach to this type of coupling.

The range of possible values for a fire danger index or component, given a set of NFDRS parameters and weather input.

A hose coupling with one or more cylindrical studs on its outside rim. The studs allow the use of a spanner wrench to tighten the coupling.

The process by which a gas becomes a liquid.

Any road or trail formed by the process of skidding logs from stump to landing.

Device used to transport a 55-gallon drum (208 L) via sling on a helicopter.