1. To carve small sections away from something, especially a piece of wood continuously or at length. My grandfather used to sit in his armchair with a hunk of wood and his pocket knife, whittling away for hours at a time.

2. To carve small sections away from something, especially a piece of wood, to in order to shape it or make it smaller. A noun or pronoun can be used between "whittle" and "away." We used to sit on our back porch and whittle away blocks of soap into the shapes of tiny animals. I had to keep whittling the edge of the door away until it finally fit into the frame properly.

3. To reduce or eliminate the size, scope, or strength of something by incrementally removing small parts. A noun or pronoun can be used between "whittle" and "away." If they keep whittling away our budget like this, our department will have to close down before too long. The president's administration continued to whittle away the powers of congress and the courts until he had complete control of the country. Having to write a thesis this length was daunting, but I've just whittled it away every day for the last three months.