An expanse of land or water. A specified or limited area of land: developing a 30-acre tract. Anatomy A system of organs and tissues that together perform a specialized function: the alimentary tract. Anatomy A bundle of nerve fibers having a common origin, termination, and function. Archaic A stretch or lapse of time. A leaflet or pamphlet containing a declaration or appeal, especially one put out by a religious or political group. The verses from Scripture sung during Lent or on Ember Days after the gradual in the Roman Catholic Mass.