Your uncle. Assuming your aunt is a sibling of one of your parents, your uncle would be defined as whoever happens to be married to her. You're welcome to continue calling the first husband your uncle if you feel it's appropriate.
By his name. Generally, you address a man as Mr. Lastname until he directs you to call him by his first name. If your aunt introduces him by his first name, you can go ahead using that.
You can call him by his first name but if your comfertable and your aunt says it's okay, call him uncle whatever (: lol
Your aunts and uncles are the sisters and brothers of your parents. So they are "blood related." But you also call the husband of your mother's sister your uncle, and he is not "blood related." So aunts and uncles are not always really related to you.
the daughter's cousin
She's technically your aunt-in-law. You obviously wouldn't actually call her "Aunt in law Sally", so you should just refer to her as "Aunt Sally."
Aunts.
They'd be your cousin.
2nd Cousin
Your grandmother's sisters are your Great Aunts.
We Puerto Ricans call aunts tee tee but the Mexicans call them Tia
Your mother's aunt's husband's sister is your mother's aunts sister-in-law but is not related to you. Her son is not related to you either.
anta! (thats what scinents call ants that are aunts)
you call a husband on twitter a twubby !
we call husband as 'bava' telugu