from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Weighing less than is normal, healthy, or required.
- n. Insufficiency of weight.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Of an inappropriately or unusually low weight.
- adj. Not too heavy for an intended purpose.
- adj. Being less invested in a particular area than market wisdom suggests.
- n. The state or quality of being underweight.
- v. To underestimate the weight of.
- v. To give insufficient weight to (a consideration); to underestimate the importance of.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. being very thin
under- + weight. (Wiktionary)