姑妈 (gūmā): This term refers to one's father's sister. She is your aunt on your father's side.
姑姑 (gūgū): Similar to 姑妈, 姑姑 also refers to one's father's sister. It is another way to address your aunt on your father's side.
叔叔 (shūshu): This term refers to one’s father’s younger brother or any man who is older than you but younger than your parents.