Formal:
* आंटी (Aanti): This is the most common and general way to address an older woman, similar to "auntie" in English.
Informal:
* बुआ (Bua): This refers to a father's sister.
* चाची (Chachi): This refers to a mother's sister.
* मासी (Maasi): This refers to a mother's younger sister.
* फूफी (Fufi): This refers to a father's younger sister.
Note:
* Using "Aanti" is a safe bet in most situations.
* The other terms are more specific and are usually used when referring to a particular aunt.
* You can also use a combination of the formal and informal terms, such as "Aanti Bua" or "Aanti Chachi."
It's always best to be respectful and use the term that is most appropriate for the situation and your relationship with the person.