Cousin sister (noun): a female first cousin. First cousins once removed are called aunt or uncle to their relative. A cousin is someone who shares one of the same genes as you and therefore can be related to you through your parents. Cousins can include siblings, children, spouses, aunts, uncles, nieces, and nephews. A sibling is another member of the same family who is born at about the same time as you or later. A brother or sister. First cousins once removed are called cousin or auntie to their relative. They can only be relatives of the original person mentioned. For example, if Susan is my cousin and Julie is her daughter, then Susan and I are first cousins once removed because we both share a common ancestor, but Susan and Julie would not be second cousins because they're not members of the same family as each other. Second cousins may also be referred to as third cousins due to the fact that they are three generations away from a shared ancestor. For example, Susan's mother Evelyn is my third-grade teacher, while Julie is Evelyn's granddaughter.