tract

nouns

an extended area of land
parcel, parcel of land, piece of ground, piece of land, tract
a system of body parts that together serve some particular purpose
tract
is a type of (narrower)
a group of physiologically or anatomically related organs or parts
"the body has a system of organs for digestion"
system
a brief treatise on a subject of interest; published in the form of a booklet
pamphlet, tract
a bundle of myelinated nerve fibers following a path through the brain
nerve pathway, nerve tract, pathway, tract