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

Earlier this year, Boeing had a propellant leak during a test of its emergency abort system. Christian Davenport, The Seattle Times, "NASA to launch safety review of SpaceX and Boeing," 20 Nov. 2018 There haven’t been a ton of conclusive studies about vaping essential oils, flavorings, and propellants that can be in vaping fluids, but a preliminary study on cells suggest that some flavorings might cause cell damage. Cheryl Wischhover, Vox, "These new vape companies want you to inhale ... vitamins," 24 Oct. 2018 Breathe uses vegetable glycerin as its propellant, whose long-term effects when inhaled are not known. Cheryl Wischhover, Vox, "These new vape companies want you to inhale ... vitamins," 24 Oct. 2018 However, this means that when SpaceX starts flying NASA astronauts for the Commercial Crew Program, passengers will have to board the rocket before propellant has been loaded. Loren Grush, The Verge, "NASA might let SpaceX fuel rockets with astronauts on board," 20 Aug. 2018 Villaraigosa embodies the community most targeted by Trump, but his ethnicity has not appeared to serve as a propellant. Scott Wilson, Washington Post, "California’s race for governor has become a referendum on resistance," 3 June 2018 Water can be split apart and made into rocket propellant, which could then be used to launch spacecraft to and from the lunar surface. Loren Grush, The Verge, "NASA scraps a lunar surface mission — just as it’s supposed to focus on a Moon return," 27 Apr. 2018 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

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

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Time Traveler for propellant

The first known use of propellant was in 1644

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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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More from Merriam-Webster on propellant

Rhyming Dictionary: Words that rhyme with propellant

Spanish Central: Translation of propellant

Nglish: Translation of propellant for Spanish Speakers Encyclopedia article about propellant

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