Definition of "spacer"

spacer

/ˈspeɪsə(ɹ)/

noun
plural spacers
1. (science fiction) A person who works or lives in space.
  Quotations
  It was the futile throwing back in the face of the Spacers their most keenly felt insult: their insistence on considering the natives of Earth as disgustingly diseased.
  1954, Isaac Asimov, The Caves of Steel
  "How do I know I can trust you?" asked BKR.Grakker hesitated. "Spacer's oath," he said at last.
  2014 , Bruce Coville, Aliens Ate My Homework‎, page 134
  Shepard: What are you running for?Charles Saracino: I'm seeking one of the five spacer seats in Parliament. They have certain baroque conditions for a citizen to be able to vote for them.Charles Saracino: You have to spend more than six months a year in space. But you can't have stayed in any one settled system for more than a month.
  2008, BioWare, Mass Effect (Science Fiction), Redwood City: Electronic Arts, PC, scene: Citadel
  He was thankful that he still had his suit on when the ship had a catastrophic decompression, a spacer's worst nightmare.
  2017, A.K. Brown, Humans on the Menu (Champagne Universe Series: Book 2), page 20
2. An object inserted to hold a space open in a row of items, e.g. beads or printed type.
3. A bushing.
4. (slang) A forgetful person; one who spaces out.
5. (medicine) A type of add-on device used by an asthmatic person to increase the effectiveness of a metered-dose inhaler.
6. (historical) An instrument for reversing a telegraphic current, especially in a marine cable, to increase the speed of transmission.