ap·pur·te·nance /ə-'pərt-ən-əns/ n [Anglo-French apurtenance, alteration of Old French apartenance, from apartenant appurtenant]: property (as an outbuilding or fixture) or a property right (as a right of way) that is incidental to a principal property and that passes with the principal property upon transfer
Merriam-Webster’s Dictionary of Law. Merriam-Webster. 1996.