(1) Having a huge appetite. (2) Very eager.
Example:
One of the hardest parts of dieting is watching skinny people with voracious appetites consume large amounts of food without gaining weight.
Voracious can be applied to both people and their appetites. Teenagers are voracious eaters because they have voracious appetites. Some vacationers become voracious readers; others are voracious for other kinds of pleasure. Voracious often suggests an appetite in excess of what is good for us. We are sometimes told that we are a nation of voracious borrowers because of our voracious demand for consumer goods and voracious government spending, and none of this is good news.