Or is it ‘cubed’ steak? It’s not cube-shaped.
My dictionary defines “cubing” as tenderizing meat by breaking the fibers with superficial cuts in a pattern of squares.
No, it’s not, but there are tiny little squares in it. Have you ever seen it raw? http://www.foodsubs.com/Photos/cubesteak.jpg
You might condider the probability that the originak term was “cubed” steak!
EZ
Yup. Just like you see these stands selling “shave” ice. I’m sure it used to be “shaved” ice. I hate subliterate shit like that.
My mother used to have a “cuber” (Not what Massachusettsans call that island south of Florida). It was a roller-shaped device on a handle, with the surface of the roller being pyramidal points that were the apexes of cubes. Rolling this repeatedly across a tough cut of meat would tenderize it and make it passably enjoyable eating.
The process was of course “cubing” and I suspect that “cube steak” was originally “cubed steak” 
I have a mallet-type device with the same points, used for the same purpose of tenderizing meat.
Yes, it’s “cubed” steak. “Ice” tea, anyone?
The term seems to appear first as “cube steak” around the teens in the US.