from The American Heritage® Dictionary of the English Language, 4th Edition
- intransitive v. To react with unnecessary or inappropriate force, emotional display, or violence.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- v. To react too much or too intensely.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- v. show an exaggerated response to something
over- + react (Wiktionary)