Mask
noun
A temporary face is something you put over your face to cover it. It's a mask.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
一つの仮面
one mask
金の仮面
gold mask
ガラスの仮面
a glass mask, Glass Mask (manga series)
アクション仮面
Action Mask (character in Crayon Shin-chan)
月光仮面
Moonlight Mask (TV and movie superhero)
タキシード仮面
Tuxedo Mask (character in Sailor Moon)
仮面家族
family that pretends to get along, The Masked Family (literature)
仮面パーティー
masquerade party
仮面ライダー
Kamen Rider (TV series)
仮面を外す
to take off a mask
仮面をつける
to put on a mask
仮面をかぶる
to wear a mask
わぁ、びっくりした！何で仮面なんてかぶってるの？
Ah, you startled me! Why are you wearing that mask?
彼女は笑顔の仮面の下で、本当は泣いているのかもしれないよ。
Behind her smiling mask, she might actually be crying.
ハロウィンの日の夜、仮面ライダーのコスプレをしながら、チョコレートを一箱平らげたビエトを見ました。
On the Halloween night, I saw Viet wearing the Masked Rider costume and eating a whole box of chocolates.