from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Slang An empty-headed or silly person.
- n. An object, such as a brick or stone, used as a missile.
- n. Slang An unspecified gadget or other small article, especially one whose name is unknown or forgotten.
- n. Printing A typographical ornament or symbol.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A silly, crazy or stupid person.
- n. A special ornamental typographical symbol, such as a bullet, an arrow, a pointing hand etc.
- n. An architectural style of apartment building, where the second storey overhangs an area for parking cars.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a silly empty-headed person
Probably ding1 + bat2 (as in bats in the belfry).(American Heritage® Dictionary of the English Language, Fourth Edition)