Procrastinate means to put off doing something until a future time. When people sit down to write term papers, they can find all kinds of clever ways to procrastinate: reorganizing the paperclips, calling everyone they know, typing "I am bored" fifty times in a row.
The verb procrastinate is from Latin prōcrāstināre, from prō- "forward" plus crāstinus "of tomorrow," from crās "tomorrow." Some synonyms are defer, postpone, and delay, though these words often apply to more positive reasons for inaction. The reason for procrastination is often assumed to be laziness, or just that the task or action is unpleasant and difficult to begin.