pro·pel·lant | \prə-ˈpe-lənt \
variants: or less commonly propellent

Definition of propellant 

(Entry 1 of 2)

: capable of propelling


variants: or less commonly propellent

Definition of propellant (Entry 2 of 2)

: something that propels: such as

a : an explosive for propelling projectiles

b : fuel plus oxidizer used by a rocket engine

c : a gas kept under pressure in a bottle or can for expelling the contents when the pressure is released

Examples of propellant in a Sentence

Recent Examples on the Web: Adjective

Luigi T. De Luca, an Italian academic and a leading expert in solid propellant rockets, said in an email. Hiroko Tabuchi, New York Times, "A Cheaper Airbag, and Takata’s Road to a Deadly Crisis," 26 Aug. 2016

Recent Examples on the Web: Noun

King explained that years of exposure to changing temperatures and humidity degraded the propellant, causing the airbags to malfunction. CBS News, "Drivers urged to fix recalled Takata airbags that can explode," 12 June 2018 The propellants being asked for would have to be liquids throughout a range of temperatures, and preferably completely innocuous and easily stored until reacting violently together upon combination. Jonathan M. Gitlin, Ars Technica, "The funniest, most accessible book on rocket science is being reissued," 4 Feb. 2018 For instance, returning back to land requires more fuel than a drone ship landing, so launches that eat up a lot of propellant during the ascent usually have to land in the ocean (if it all). Loren Grush, The Verge, "SpaceX may finally land one of its rockets on the California coast later this year," 6 July 2018 For example, the USAF Ground Systems Development and Operations Program developed a universal propellant servicing system and will construct LC-48 as a multi-use launch complex for small launch vehicles. Joe Pappalardo, Popular Mechanics, "Cape Canaveral, Reinvigorated," 12 June 2018 The autophage engine consumes a propellant rod that has solid fuel on the outside and oxidizer on the inside, according to PhysOrg. Eric Berger, Ars Technica, "Rocket Report: SpaceShipTwo soars, BFR engine advances, a self-eating booster," 1 June 2018 At the end of 2010, one Proton plunged into the ocean because too much propellant had been mistakenly loaded into its upper stage. Eric Berger, Ars Technica, "Russia’s Proton rocket, which predates Apollo, will finally stop flying," 25 June 2018 On the Space Shuttle, for instance, propellant was loaded many hours before crew boarded the vehicle. Loren Grush, The Verge, "SpaceX’s new Falcon 9 rocket still needs a key update before it can fly astronauts," 24 May 2018 During the space shuttle era, astronauts boarded the shuttle after propellants were loaded. Samantha Masunaga,, "SpaceX's controversial rocket fueling procedure appears 'viable,' says NASA safety advisory panel," 17 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'propellant.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of propellant


1644, in the meaning defined above


1654, in the meaning defined above

Keep scrolling for more

Learn More about propellant

Share propellant

Statistics for propellant

Look-up Popularity

Time Traveler for propellant

The first known use of propellant was in 1644

See more words from the same year

Keep scrolling for more

More Definitions for propellant



English Language Learners Definition of propellant

: a gas under pressure in a can that is used to spray out the contents when the pressure is released

: a fuel or an explosive substance that is used to make something (such as a rocket) go forward

Keep scrolling for more

Comments on propellant

What made you want to look up propellant? Please tell us where you read or heard it (including the quote, if possible).


required by fashion, etiquette, or custom

Get Word of the Day daily email!

Test Your Vocabulary

Great Scrabble Words—A Quiz

  • scrabble-tiles-that-read-scrabble-quiz
  • Which of the following Q-without-U words means the number five in cards or dice?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!