from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Occurring or made hastily on impulse: a spur-of-the moment choice.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Spontaneous; impromptu.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. in response to an unforeseen need
See spur of the moment (Wiktionary)