Aunt is a term used to refer to the sister of one's parent or the wife of one's uncle.
In modern slang, aunt can also mean:
1. An older woman who gives advice (like "auntie advice")
2. A term of endearment for a close female friend
3. In LGBTQ+ communities, an experienced mentor figure
4. In some cultures, any older female relative may be called "aunt" as a sign of respect