The word κυριότης occurs 4 times in the NT (not in the LXX), twice referring to Jesus’ power or position as Lord (κύριος) and twice referring to members of a class of angels (Eph. 1.21; Col. 1.16).
In extrabiblical literature, κυριότης occurs only very rarely. When it does, it has the meanings of ‘lordship, rule’ and ‘special meaning’. It is only in writings influenced by the NT that the term is used to refer to a class of angels; see the many references in Lampe’s PGL 788b. When in a fr…