What does it mean to be a cousin nine time removed?

If you and someone else are ninth cousins, then one of your great great great great great great great great grandparents was the brother or sister of one of the other's great great great great great great great great grandparents.

If you are ninth cousins, once removed, then either:

• you are the child of the other'sninth cousin, or
• the other is the child of yourninth cousin.