Late 17th century; earliest use found in Gideon Harvey (c1636–?1702), physician. From post-classical Latin terminatorius from classical Latin termināt-, past participial stem of termināre + -ōrius.
Definition of terminatory in US English:
terminatory
adjectiveˈtəːmɪnət(ə)ri
Terminal.
Origin
Late 17th century; earliest use found in Gideon Harvey (c1636–?1702), physician. From post-classical Latin terminatorius from classical Latin termināt-, past participial stem of termināre + -ōrius.