There are seven mothers according to Vedic civilization:
Real mother, from whose womb we have come to this world, real mother, atma-mata.
Then guroh patni, wife of the teacher or spiritual master, guroh patni.
Brahmani, the wife of a brahmana. Atma-mata guroh patni
the wife of the king, or the queen. She’s also mother.
Dhenu- Cow is also mother.
Dhatri -Nurse is also mother.
Tatha pruthvi- The Earth is also our mother. That we say in country, in the country which we take birth.
In Sanskrit it is called desa-matrka. That is also mother. Mother land, mother language So many mothers we have got, out of which, cow is also mother. Therefore she’s addressed as amba. Amba means mother. Still in Gujarat province, they call amba. And in other provinces of India, they also call Amma in broken language.That is from very long time there is a big temple of Amba devi-Mother Durga, Kali, in Bombay. So this Amba-devi was pronounced by the Englishmens as Bamba-devi, and from Bamba-devi it has come to “Bombay.”
Ref >> Srila Prabhupada Vani.