the financial relationship between interest (child) and the principal or capital (mother)

古代的高利贷计息往往涉及子母相权。

noun · the relationship or literal pairing of a mother and her son

这对子母在战乱中失散多年。

a set or combination of a large object and a smaller one of the same type

安装子母门可以方便大件家具进出。