The term "first uncle" has no special meaning in the English language.
uncles
Your uncle's son is your first cousin.
Yes if you will mean that uncles posses something. Examples: uncles' houses (the houses of uncles) uncles' children (the children of uncles)
Cousin. Your parents brothers and sisters are aunts and uncles. and the aunt and uncles children are your cousins.
His great uncle
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.
uncle's My uncle's dog is very big.
he had 3 uncles
There are 4 uncles in a pound.
your uncles daughter would be your cousin
Your aunts and uncles are the sisters and brothers of your parents.
he first played on his uncles in the late 40;s and he received the first from his parents around age 12