Presenting a self that is not one's own in order to be accepted. Masking is a skill demanded, then pathologised, and it exhausts the one who does it.
French masque (a covering for the face), from Italian maschera, of disputed ultimate origin — perhaps Arabic maskharah (buffoon) or medieval Latin masca (spectre); presenting a face that is not one's own in order to be accepted.
A survival skill turned into a diagnosis — the cost of being accepted paid in exhaustion by the one doing the presenting.