1540s, from Middle French procrastination and directly from Latin procrastinationem (nominative procrastinatio) "a putting off from day to day," noun of action from past participle stem of procrastinare "put off till tomorrow, defer, delay," from pro- "forward" (see pro-) + crastinus "belonging to tomorrow," from cras "tomorrow," of unknown origin.[procrastination etymology, procrastination origin, 英语词源]