from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The soft, fine undercoat of certain mammals, such as otters, beavers, and seals.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The thick, soft undercoat of some mammals, especially those that spend time in the water
from The Century Dictionary and Cyclopedia
- n. The coat of soft, fine hair, or fur, found in many mammals, overlain by longer, coarser hairs. The underfur forms the principal furs of commerce, such as the beaver, otter, fur-seal, etc.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. thick soft fur lying beneath the longer and coarser guard hair
under- + fur (Wiktionary)