What is Appurtenance?

Alternative Forms: Appurtenances
Legal Definition
Appurtenances are things that belong to and go with something else, the appurtenance being less significant than what it belongs to. The word ultimately derives from Latin appertinere, "to appertain".

In a legal context, an appurtenance could for instance refer to a back-yard that goes with the adjoining house. The idea being expressed is that the back-yard "belongs" to the house, which is the more significant of the two. In 1919, the Supreme Court of Minnesota adopted the following definition of an appurtenance: "That which belongs to something else. Something annexed to another thing more worthy." – Cohen v Whitcomb, (1919 142 Minn 20).

In Gestalt theory, appurtenance (or "belongingness") is the relation between two things seen which exert influence on each other. For example, fields of color exert influence on each other. "A field part x is determined in its appearance by its 'appurtenance' to other field parts. The more x belongs to the field part y, the more will its whiteness be determined by the gradient xy, and the less it belongs to the part z, the less will its whiteness depend on the gradient xz."

In lexicology, an appurtenance is a modifier that is appended or prepended to another word to coin a new word that expresses "belongingness". In the English language, appurtenances are most commonly found in toponyms and demonyms, for example, 'Israeli', 'Bengali' etc. have an -i suffix of appurtenance.
-- Wikipedia
Legal Definition
In common parlance and legal acceptation, is used to signify something belonging to another thing as principal, and which passes as incident to the principal thing. 10 Peters, R. 25; Angell, Wat. C. 43; 1 Serg. & Rawle, 169; 5 S. & R. 110; 5 S. & R. 107; Cro. Jac. 121 3 Saund. 401, n. 2; Wood's Inst. 121 Rawle, R. 342; 1 P. Wms. 603; Cro. Jac. 526; 2 Co. 32; Co. Litt. 5 b, 56 a, b; 1 Plowd. 171; 2 Saund. 401, n. 2; 1 Lev. 131; 1 Sid. 211; 1 Bos. & P. 371 1 Cr. & M. 439; 4 Ad., & Ell. 761; 2 Nev. & M. 517; 5 Toull. n. 531. 2. The word appurtenances, at least in a deed, will not pass any corporeal real property, but only incorporeal easements, or rights and privileges. Co. Lit. 121; 8 B. & C. 150; 6 Bing. 150; 1 Chit. Pr. 153, 4. Vide Appendant.
-- Bouviers Law Dictionary
Legal Definition
That which belongs to something else; an adjunct; an appendage ; something annexed to another thing more worthy as principal, and which passes as incident to it, as a right of way or other easement to land; an out-house, barn, garden. or orchard, to a house or messuage. Meek v. Breckenridge, 29 Ohio St. 642; Harris v. Elliott, 10 Pet. 54, 9 L. Ed. 333; Humphreys v. McKissock, 140 U. S. 304, 11 Sup. Ct 779, 35 In Ed. 473; Farmer v. Water Co., 56 Cal. 11. Appurtenances of a ship include whatever is on board a ship for the objects of the voyage and adventure in which she is engaged, belonging to her owner. Appurtenant is substantially the same in meaning as accessory, but it is more technically used in relation to property, and is the more appropriate word for a conveyance.
-- Black's Law Dictionary
Legal Definition
A thing that is part of another thing even though it is detached.
Legal Definition
Things which are appurtenant. See 64 Am. St. Rep. 107.
-- Ballentine's Law Dictionary