Dating my third cousin
Sometimes you and your cousin may share a common ancestor, but you each call this ancestor something different.For example, the common ancestor may be great-great grandparent.Your first cousin twice removed is the child of your first cousin once removed (i.e. Your second cousin twice removed is the child of your second cousin once removed (i.e. REMOVED COUSINS: If two people are some type of cousins, but they are at different generation levels, then here is the way to compute their relationship.
(Once removed means one generation level different from you.) All your regular cousins (first, second, etc.) are at the same generation level as yourself.
Your uncle is the brother of your father or mother. Your great uncle (or grand uncle) is the brother of your grandfather or grandmother.
Your great aunt is the sister of your grandfather or grandmother.
This is the "FIRST" or "SECOND" or "THIRD" part of the cousin relationship.
More generally, cousin is a type of familial relationship in which people with a known common ancestor are both two or more generations away from their most recent common ancestor.
This is where the phrase “once removed” comes in handy.