noun
A somewhat literary or traditional term for an old woman; in everyday speech おばあさん is more common.
昔話には、よく姥が登場する。
Old women often appear in folk tales.
noun
Noh mask of an old woman
A specific mask used in Noh theater to represent an elderly female character.
能楽堂で姥の面を見た。
I saw the old woman mask at the Noh theater.
The standard polite and everyday word for an elderly woman or one's grandmother. 姥 is more literary and traditional.
The historical derivation is uncertain; the kanji 姥 is conventionally associated with the meaning 'old woman'.