After a divorce is a uncle still a uncle?

If he is your uncle by marriage (married to your aunt) which later ends in divorce, he is no longer truly an uncle in the technical sense. However, he may still be said to be your uncle in the sense...

Legally,no, but if you love your uncle then he'll always be your uncle...no matter what! Oh and of course if your uncle is your mother/father's brother, of course cos he's blood related-YAY!

Formally, she stops being your aunt when they divorce; but that does not mean you can't still keep contact and be friends if you both want to.

Yes.