This is the 7381st most frequent Japanese word.
仮面
Mask.
In this sentence, '仮面' is used to mean 'mask', referring to an article covering the face for concealment or decoration.
彼はパーティーで黒い仮面をかぶった。
He wore a black mask at the party.
Here, '仮面' metaphorically represents a facade or false front that hides one's true emotions or intentions.
彼の笑顔は仮面であり、内心は違った。
His smile was a mask, and his true feelings were different.
In this context, '仮面' is a focal object in the narrative, often symbolizing something secret or mysterious.