from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The latest possible time: turned in the report at the eleventh hour.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A point in time which is nearly too late; the last minute.
- n. Used attributively.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the latest possible moment
From a story in the Bible of workmen hired at the eleventh hour (that is, late in the day): (Wiktionary)