伯母
bó mǔ · HSK 7
wife of father's elder brother
👩 bó mǔ = elder-father + mother — your uncle's wife, an auntie figure
伯 (bó) means 'elder brother of father' and 母 (mǔ) means 'mother.' Together they literally say 'elder-uncle's mother-figure,' i.e. the wife of your dad's older brother. Also used as a polite address for any woman your mom's age.
母 — pictograph of kneeling woman with two breast dots
母 is a pictograph derived from 女 (woman) with two added dots representing breasts, marking a nursing mother. The earliest oracle bone forms show a kneeling figure with prominent dots on the chest. The meaning has stayed remarkably stable, denoting 'mother' and by extension 'female' or 'source/origin'.