It is similar to proxvir, the main difference being that it is not derived from maleness or masculinity in any way. It is the masculine equivalent of contrafe. The androgynous equivalent is contrandrog.
Contramas is a combination of the Latin words contra, meaning against, and mas, meaning masculine.
The term was coined by Fandom user Foxesforever on March 15, 2021.
The flag was created by the same user on the same date. It has no confirmed meaning.