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adjective caus·tic \ˈkȯs-tik\

Simple Definition of caustic

  • : able to destroy or burn something by chemical action

  • : very harsh and critical

Source: Merriam-Webster's Learner's Dictionary

Full Definition of caustic

  1. 1 :  capable of destroying or eating away by chemical action :  corrosive

  2. 2 :  marked by incisive sarcasm

  3. 3 :  relating to or being the surface or curve of a caustic

caustically play \-ti-k(ə-)lē\ adverb
causticity play \kȯ-ˈsti-sə-tē\ noun

Examples of caustic in a sentence

  1. His [Roosevelt's] caustic cousin, Alice Roosevelt Longworth, called him a sissy and a mama's boy. —Garry Wills, Atlantic, April 1994

  2. 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

  3. 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

  4. The chemical was so caustic that it ate through the pipes.

  5. She wrote a caustic report about the decisions that led to the crisis.

Did You Know?

If you have a burning desire to know the origins of "caustic," you're already well on the way to figuring it out. "Caustic" was borrowed into English in the 14th century from the Latin causticus, which itself derives from the Greek kaustikos. "Kaustikos," in turn, comes from the Greek verb kaiein, meaning "to burn." Other "kaiein" descendants in English include "cautery" and "cauterize," "hypocaust" (an ancient Roman heating system), "causalgia" (a burning pain caused by nerve damage), and "encaustic" (a kind of paint which is heated after it's applied).

Origin of caustic

Latin causticus, from Greek kaustikos, from kaiein to burn

First Known Use: 14th century

Synonym Discussion of 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>.

Other Chemical Engineering Terms



noun caus·tic \ˈkȯs-tik\

Definition of caustic

  1. 1 :  a caustic agent: as a :  a substance that burns or destroys organic tissue by chemical action b :  sodium hydroxide

  2. 2 :  the envelope of rays emanating from a point and reflected or refracted by a curved surface

Origin of caustic

(see 1caustic)

First Known Use: 15th century

Other Chemical Engineering Terms

CAUSTIC Defined for Kids


adjective caus·tic \ˈkȯ-stik\

Definition of caustic for Students

  1. 1 :  capable of eating away by chemical action :  corrosive

  2. 2 :  very harsh and critical <caustic remarks>

Medical Dictionary



adjective caus·tic \ˈkȯ-stik\

Medical Definition of caustic

  1. :  capable of destroying or eating away organic tissue and especially animal tissue by chemical action <silver nitrate and sulfuric acid are caustic agents>

caustically \-sti-k(ə-)lē\play adverb
causticity \kȯ-ˈstis-ət-ē\play noun plural causticities



noun caus·tic

Medical Definition of caustic

  1. :  a caustic agent: asa:  a substance that burns or destroys organic tissue by chemical action :  escharoticb:  a strong corrosive alkali (as sodium hydroxide)

Seen and Heard

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tending to dismiss important matters

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