field of fire vs tract

field of fire and tract both are nouns.

Word	Noun	Adjective	Verb	Adverb
field of fire	Yes	No	No	No
tract	Yes	No	No	No

As nouns, tract is a hypernym of field of fire; that is, tract is a word with a broader meaning than field of fire:

field of fire: the area that a weapon or group of weapons can cover effectively with gun fire from a given position
tract: an extended area of land

Other hypernyms of field of fire include parcel, parcel of land, piece of ground, piece of land.

field of fire (noun)	tract (noun)
the area that a weapon or group of weapons can cover effectively with gun fire from a given position	a bundle of myelinated nerve fibers following a path through the brain
	a system of body parts that together serve some particular purpose
	a brief treatise on a subject of interest; published in the form of a booklet
	an extended area of land