from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The volume left at the top of an almost filled jar, tin, or other container before sealing.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The space between the top of the contents of a container (such as a jar) and its seal (such as a lid).
- n. One's mental state.
- n. The gap between the face of the bolt and the stopping surface for the cartridge.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the volume left at the top of a filled container (bottle or jar or tin) before sealing
head + space (Wiktionary)