To fulfill means to complete something you promised or were supposed to do. When you fulfill a promise to help your younger sibling with homework, you actually follow through and do it. When a company fulfills your online order, they pack up what you bought and send it to you.

The word carries a sense of satisfaction and completion. Teachers fulfill their responsibilities by preparing lessons and helping students learn. A baker fulfills customer orders by making the exact cakes people requested. When you fulfill the requirements to earn a badge in Scouts, you've done everything necessary to achieve it.

You can also fulfill a need or desire, meaning you satisfy it completely. A good meal fulfills your hunger. An exciting book might fulfill your need for adventure. When something is fulfilling, it gives you a deep sense of satisfaction and purpose, like when hard work on a science project leaves you feeling proud and accomplished.

The related word fulfillment describes both the act of completing something and the satisfying feeling you get from doing meaningful work. A warehouse might handle order fulfillment, while you might find fulfillment in mastering a difficult piano piece.