from The American Heritage® Dictionary of the English Language, 4th Edition
- adv. Excessively; immoderately: unduly familiar with strangers.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adv. Undeservedly, not warranted.
from the GNU version of the Collaborative International Dictionary of English
- adv. In an undue manner.
from The Century Dictionary and Cyclopedia
- In an undue manner or degree; wrongly; improperly; excessively; inordinately.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adv. to an undue degree
undue + -ly (Wiktionary)