OK, I have:(from "the international dictionary of physics and electronics, second edition 1961, D. Van Nostrand Co.)
Rest Frame: Lorentz frame in which the total momentum of a system vanishes.
AND
Lorentz Frame: Any of the set ofcoordinate systems in Minkowski space for which the square of the interval between two events is c^2dt^2-(dx)^2.
Any such coordinate system may be obtained from another by means of Lorentz transformation (together perhaps, with an orthagonal transformation of the space axes). With each Lorentz may be associated a point observer, each of whom moves with constant velocity relative to the others.