California Code, Government Code - GOV § 51177

(a) “Defensible space” means the area adjacent to a structure or dwelling where wildfire prevention or protection practices are implemented to provide defense from an approaching wildfire or to minimize the spread of a structure fire to wildlands or surrounding areas.

(b) “Director” means the Director of Forestry and Fire Protection.

(c) “Fuel” means any combustible material, including petroleum-based products, cultivated landscape plants, grasses, and weeds, and wildland vegetation.

(d) “Fuel management” means the act or practice of controlling flammability and reducing resistance to control of fuels through mechanical, chemical, biological, or manual means or by fire, in support of land management objectives.

(e) “Local agency” means a city, county, city and county, or district responsible for fire protection within a very high fire hazard severity zone.

(f) “Single specimen tree” means any live tree that stands alone in the landscape so as to be clear of buildings, structures, combustible vegetation, or other trees, and that does not form a means of rapidly transmitting fire from the vegetation to an occupied dwelling or structure or from an occupied dwelling or structure to vegetation.

(g) “State responsibility areas” means those areas identified pursuant to Section 4102 of the Public Resources Code.

(h) “Vegetation” means all plants, including trees, shrubs, grass, and perennial or annual plants.

(i) “Very high fire hazard severity zone” means an area designated as a very high fire hazard severity zone by the State Fire Marshal pursuant to Section 51178 that is not a state responsibility area.

(j) “Wildfire” means an unplanned, unwanted wildland fire, including unauthorized human-caused fires, escaped wildland fire use events, escaped prescribed fire projects, and all other wildland fires where the objective is to extinguish the fire.