superficiary
/ˌs(j)uːpəˈfɪʃ(ə)ri/ /ˌs(j)uːpəˈfɪʃɪəri/adjective
Roman Law and Civil Law. Designating the right to use the surface of another's land for building or other purposes; of or relating to a superficiary. Compare superficial. Now somewhat rare.
noun
Roman Law and Civil Law. A person who owns property on land belonging to another; a person who has acquired the right to use the surface of another's land for building or other purposes. Compare superficial, superficies. Now somewhat rare.
Origin
Early 17th century (in an earlier sense). From classical Latin superficiārius (adjective) (of buildings) held in tenure on another person's land, (noun) person who enjoys the tenure of a building on another person's land (2nd cent. a.d. in legal context), in post-classical Latin also superficial from superficiēs + -ārius.