from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Informal A grandfather.
- n. Informal One that is the first, oldest, or most respected of its kind: the granddaddy of modern computers.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A grandfather.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the father of your father or mother
Diminutive of granddad. (Wiktionary)