head-space

Noun

headspace (countable and uncountable, plural headspaces)

1. The space between the top of the contents of a container (such as a jar) and its seal (such as a lid).
   • Control of headspace is important for economic and technical reasons. Underfilling will contravene Weights and Measures legislation and may cause rusting in the headspace […]1997, S. D. Holdsworth, “Food Preservation Processes”, in M. D. Ranken, R. C. Kill, C. Baker, editors, Food Industries Manual, 24th edition, Blackie Academic and Professional, →ISBN, page 517

   Synonyms:

   headroom, ullage

2. (informal) One's capacity for mental activity modeled as a physical space with limits.
   • Meronym: mindshare

   Synonyms:

   brainspace

3. One's mental state or state of mind.
   • Many of us, as gays, have been in the same headspace as Maurice: longing, lonely, and scared.1971, Herb Spiers, “Maurice (review)”, in Body Politic, number 1, page 12
4. (informal) A time and opportunity for reflection and thinking.
   • As a business owner, a truly effective business owner that is building a profitable business machine, you need headspace, thinking time, planning time, brainstorming time, education time, decision making time, questioning time and more thinking time.2011, Eric J. Gregory, Would You Like Profits, →ISBN
5. The gap between the face of the bolt and the stopping surface for the cartridge.
6. The gas phase in contact and in equilibrium with a nonvolatile liquid in a sample.

See all 8 meanings of headspace