A group of axons linking two or more neuropils and having a common origin, termination[FBbt]. [ http://flybrain.uni-freiburg.de/Flybrain/html/terms/terms.html https://github.com/obophenotype/uberon/issues/286 ]
Synonyms: neuraxis tract tract of neuraxis axonal tract
WP says this is the analog of peripheral nerves in CNS.
White matter structure of CNS that contains axons that arise predominantly in one central nervous system part and terminate in another. Tracts are generally named by their region or origin followed by their region of primary termination, e.g., mammillothalamic tract contains axons that arise from neurons in the mammillary bodies and terminate in the thalamus. (CUMBO)