pro·​pel·​lant | \ prə-ˈpe-lənt How to pronounce propellant (audio) \
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 This means that an air-breathing rocket can lift more stuff with less propellant and drastically lower the cost of space access—at least in theory. Daniel Oberhaus, Wired, "The Rocket Motor of the Future Breathes Air Like a Jet Engine," 26 June 2020 Successfully completing the cross-country train trip from Utah to Florida were all 10 propellant segments for the Artemis I mission of the SLS rocket, reports. Eric Berger, Ars Technica, "Rocket Report: Another no-go for MOMO rocket, SpaceX invests in McGregor," 19 June 2020 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 During this standard prelaunch test, an Atlas V rocket is fueled with propellant and a countdown is conducted until the final moments before ignition. Eric Berger, Ars Technica, "NASA’s next Mars mission has now burned nearly half of its launch window," 30 June 2020 The uranium fuel used in nuclear reactors has an energy density that is 4 million times higher than hydrazine, a typical chemical rocket propellant. Popular Science, "The next era of space travel should include nuclear-powered rockets," 27 May 2020 Documents posted Thursday by the US National Highway Traffic Safety Administration say Takata packed in too much ammonium nitrate propellant while manufacturing the inflators., "Healey asks DPU to delay natural gas rate increases for pipeline replacements," 3 Apr. 2020 Most of the rocket's delays have centered on the rocket's Core Stage, which houses large liquid oxygen and hydrogen propellant tanks, and four space shuttle main engines. Eric Berger, Ars Technica, "Space Launch System rocket now targeted for a late 2021 launch," 14 May 2020 Weislogel envisioned pump-less systems where liquid moves based on the shape and size of containers, like fuel depots that can orbit the moon and transfer propellant to a spacecraft without a pump. Ashley Strickland, CNN, "Astronauts experimented with Nickelodeon's slime in space," 13 May 2020 Weapons experts say North Korea also is developing an ICBM that uses solid-propellant technology, potentially giving the U.S. less warning ahead of any strike aimed at the mainland. Jon Herskovitz | Bloomberg, Washington Post, "How Kim Jong Un Keeps Advancing North Korea’s Nuclear Program," 13 Dec. 2019 Because of the fluffy nature of Trail Boss powder, ignition is more consistent and propellant burn more complete with a crimp. Jeff Johnston, Field & Stream, "The Pros and Cons of Subsonic Cartridges," 8 Oct. 2019 What’s more, modern machining advancements, material improvements and the development of more effective projectiles and propellants have made muzzleloading rifles incredibly reliable and accurate. Brad Fitzpatrick, Outdoor Life, "The 8 Best Modern Muzzleloaders," 26 Feb. 2019

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.

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First Known Use of propellant


1644, in the meaning defined above


1654, in the meaning defined above

History and Etymology for propellant


borrowed from Latin prōpellent-, prōpellens, present participle of prōpellere "to push or thrust forward, compel to go onward" — more at propel


in part noun derivative of propellant entry 1, in part from propel + -ant entry 1

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Time Traveler for propellant

Time Traveler

The first known use of propellant was in 1644

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Statistics for propellant

Last Updated

10 Jul 2020

Cite this Entry

“Propellant.” Dictionary, Merriam-Webster, Accessed 11 Jul. 2020.

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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

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