Mascgirlflux is when you identify as a female, however your intensity fluctuates heavily from feminine to masculine and back in such a way it's affecting the person's representation.
The term derives from masc - for masculine, from girl - for female, and from flux - how one feels the intensity.
The counterpart to this Is Femboyflux.
Flag
The dark pink in the middle represents the core gender, which is female. The layers of pink represent the level of femininity, and the layers of blue represent the level of masculinity.