caustic

1 of 2

adjective

caus·​tic ˈkȯ-stik How to pronounce caustic (audio)
1
: capable of destroying or eating away by chemical action : corrosive
The chemical was so caustic that it ate through the pipe.
2
: marked by incisive sarcasm
a caustic film review
caustic humor
3
: relating to or being the surface or curve of a caustic (see caustic entry 2 sense 2)
caustically adverb
causticity noun

caustic

2 of 2

noun

1
: a caustic agent: such as
a
: a substance that burns or destroys organic tissue by chemical action
b
: a strong corrosive alkali (such as sodium hydroxide)
2
: the envelope of rays emanating from a point and reflected or refracted by a curved surface

Did you know?

If you have a burning desire to know the origins of caustic, you're already well on your way to figuring it out. Caustic was formed in Middle English as an adjective describing chemical substances, such as lime and lye, that are capable of destroying or eating away at something. The word is based on the Latin adjective causticus, which itself comes ultimately from the Greek verb kaiein, meaning "to burn." In time, caustic was baked into the English language as an adjective describing people or things (such as wit or remarks) that are bitingly sarcastic. Other kaiein descendants in English include cautery and cauterize, causalgia (a burning pain caused by nerve damage), and encaustic (a kind of paint that is heated after it's applied).

Choose the Right Synonym for caustic

caustic, mordant, acrid, scathing mean stingingly incisive.

caustic suggests a biting wit.

caustic comments

mordant suggests a wit that is used with deadly effectiveness.

mordant reviews of the play

acrid implies bitterness and often malevolence.

acrid invective

scathing implies indignant attacks delivered with fierce severity.

a scathing satire

Examples of caustic in a Sentence

Adjective His [Roosevelt's] caustic cousin, Alice Roosevelt Longworth, called him a sissy and a mama's boy. Garry Wills, Atlantic, April 1994
It was Schuyler's gift for satire and his caustic wit that distinguished his writings and led to his nickname, the Black Mencken. Henry Louis Gates, Jr., New York Times Book Review, 20 Sept. 1992
Albert quailed before those caustic pronouncements, he shuddered and blanched and felt his stomach drop like a croquette into a vat of hot grease. T. Coraghessan Boyle, Harper's, October 1987
The chemical was so caustic that it ate through the pipes. She wrote a caustic report about the decisions that led to the crisis.
Recent Examples on the Web
Adjective
The following weeks were filled with a caustic exchange of letters between the universities, including one from prominent SDSU boosters demanding that BYU launch an internal investigation. Mark Zeigler, San Diego Union-Tribune, 7 Mar. 2024 The earnestness of his jabs didn’t jibe with the post-satirical age ushered in by Donald Trump’s surreal presidency, in which younger, left-leaning audiences have gravitated toward more caustic humor. David Sims, The Atlantic, 13 Feb. 2024 There are special rules regarding vandalizing places of worship, vandalism using caustic chemicals and vandalism on or near a highway or freeway. Hanh Truong, Sacramento Bee, 16 Feb. 2024 Now an independent artist, he reportedly was denied distribution services from numerous companies due to his caustic antisemitic remarks. Steven J. Horowitz, Variety, 15 Feb. 2024 Even as adults, depression, anxiety and other mental illnesses can impact the brain’s ability to function, while emotional trauma, such as domestic violence, rape, loss of a child, spouse or job can also flood the brain with caustic stress hormones that take a toll over time. Sandee Lamotte, CNN, 12 Feb. 2024 The caustic gunk is usually relegated to giant landfills, unless something like an industrial accident unleashes torrents of the sludge, as was unfortunately the case for rural Hungarian residents back in 2010. Andrew Paul, Popular Science, 7 Feb. 2024 Overall, the beauty of revisiting Red is that many of us, at points high and low, have related to its caustic, dizzying array of emotion, tracing the nonlinear trajectory of falling in love, breaking your heart, and putting it back together again. Allaire Nuss, EW.com, 6 Feb. 2024 Capitalism, as a couple of caustic observers once noted, makes everything solid melt into uncertain air, even collapsing the seasons one into the next. Adam Gopnik, The New Yorker, 27 Jan. 2024

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'caustic.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

Adjective and Noun

Latin causticus, from Greek kaustikos, from kaiein to burn

First Known Use

Adjective

14th century, in the meaning defined at sense 1

Noun

15th century, in the meaning defined at sense 1

Time Traveler
The first known use of caustic was in the 14th century

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Dictionary Entries Near caustic

Cite this Entry

“Caustic.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/caustic. Accessed 18 Mar. 2024.

Kids Definition

caustic

1 of 2 adjective
caus·​tic ˈkȯ-stik How to pronounce caustic (audio)
1
: capable of eating away by chemical action : corrosive
2
: likely to offend or hurt someone's feelings
a caustic remark
caustically adverb

caustic

2 of 2 noun
: a caustic substance (as caustic soda)

Medical Definition

caustic

1 of 2 adjective
caus·​tic ˈkȯ-stik How to pronounce caustic (audio)
: capable of destroying or eating away organic tissue and especially animal tissue by chemical action
silver nitrate and sulfuric acid are caustic agents
caustically adverb
causticity noun
plural causticities

caustic

2 of 2 noun
: a caustic agent: as
a
: a substance that burns or destroys organic tissue by chemical action : escharotic
b
: a strong corrosive alkali (as sodium hydroxide)

More from Merriam-Webster on caustic

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