The word 姑妈 is formed by combining two characters, each representing a familial role: 姑 (gū), which specifically means "paternal aunt" (the sister of one's father), and 妈 (mā), meaning "mother". This compound creates a new, specific term that refers to one's father's married sister, linguistically embedding the respectful, maternal-like status she traditionally holds within the extended family, distinguishing her from, for example, a younger or unmarried paternal aunt (姑姑).