tract-n; 4 Senses

Sense Number 1: an expanse of land

Commentary: TRACT[+location][+geographical][+expanse]

Lewis and Clark explored and charted vast tracts of wilderness in North America.
We drove past miles and miles of tract houses. (built on tracts of land)
They have set aside a tract of farmland for the new state park.

WordNet 3.0 Sense Numbers: 1

Sense Number 2: a functional anatomical system in the body

Commentary: TRACT[+entity][+structure][+anatomical][+system][+functional][+digestive/+urinary/+nerve]

This is a detailed diagram of the human digestive tract.
The patient had an infection of the urinary tract.
These nerve tracts running through the brain are referred to as 'white matter'.

WordNet 3.0 Sense Numbers: 2, 4

Sense Number 3: a short treatise on a topic, usually scholarly

Commentary: TRACT[+entity][+artifact][+document][+treatise][+short]

One table in the bookstore was covered with tracts dealing with feminist ideology.
The Communist Manifesto is a famous political tract.
The monk wrote several tracts which were meditations on his faith.

WordNet 3.0 Sense Numbers: 3

Sense Number 4: a span of time

Commentary: TRACT[+extent][+time]

It was an idea lost through the tracts of time.
Think of the vast tracts of time required to form this giant limestone cavern.

WordNet 0.0 Sense Numbers: 1