A procrastinator is a person who delays or puts things off — like work, chores, or other actions — that should be done in a timely manner. A procrastinator is likely to leave all the Christmas shopping until December 24th.
Procrastinator comes from the Latin verb procrastinare, which means deferred until tomorrow. The prefix pro means forward, and crastinus means of or belonging to tomorrow. If you've always been known in your family as a procrastinator, your sister has probably gotten used to receiving her birthday card at Christmas time and her Christmas present in July.