from The American Heritage® Dictionary of the English Language, 4th Edition
- intransitive v. To go as fast as possible, especially in fleeing: hightailed out of town.
- idiom hightail it To hurry or flee.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- v. To retreat quickly.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- v. leave as fast as possible
From those animals that raise their tails when fleeing.(American Heritage® Dictionary of the English Language, Fourth Edition)
Refers to behavior of fleeing animals, such as deer, that raise their tail when running away. (Wiktionary)