from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The plug of tobacco ash left in the bowl of a pipe after it has been smoked.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The still burning or wholly burnt tobacco plug in a pipe.
- n. A baby's dummy, pacifier.
from The Century Dictionary and Cyclopedia
- n. A plug or tap of a vessel.
- n. A small rounded lump or mass; especially, the tobacco remaining in the bottom of a pipe after smoking, which is often put on the top of fresh tobacco when refilling.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the residue of partially burnt tobacco left caked in the bowl of a pipe after smoking
From dot1, lump (obsolete).(American Heritage® Dictionary of the English Language, Fourth Edition)
Probably from Middle English dottle or dottel, diminutives of dot ("lump or clot"), formed with -le. (Wiktionary)