Yes if you will mean that uncles posses something.
Examples:
uncles' houses (the houses of uncles)
uncles' children (the children of uncles)
If you are talking about the friend of one of your uncles, then yes: I spoke to Tom, who is my uncle's friend.
The possessive of all English plural nouns ending in s is formed by adding an apostrophe: uncles'.
Cousin. Your parents brothers and sisters are aunts and uncles. and the aunt and uncles children are your cousins.
Chiron, Bythos, Aphros would be uncles by Kronos and Philyra; by Kronos and Rhea her uncles are Poseidon and Hades, both brothers of Zeus are her uncles; on her mother's side she did not have uncles.
uncles
uncle's My uncle's dog is very big.
your uncles daughter would be your cousin
he had 3 uncles
There are 4 uncles in a pound.
Your aunts and uncles are the sisters and brothers of your parents.
No. A spider is a spider and an apostrophe is an apostrophe.
your uncles daughter would be your cousin