This concept was called electromagnetic mass, and was considered as being dependent on velocity and direction as well.
Concepts that were similar to what nowadays is called "relativistic mass", were already developed before the advent of special relativity.
The operating principle is called 'elective mass'; it is one of the assumptions that makes the inversion drive possible.
This concept is called thermal mass.
And now that what Mr. Seller calls "critical mass" has been achieved, in terms of name recognition, the advertising is likely to increase.
In the early history of relativity, the expressions and were called longitudinal and transverse mass.
Doctors may call an area of abnormal tissue a lesion or mass.
To explain himself, Van Riker drew diagrams of what he called critical mass and various other things that made only vague sense to Remo.
We also have a quality called 'mass'.
His early work (1901-1903) confirmed for the first time the velocity dependence of the electromagnetic mass of the electron (later called relativistic mass).