caustic
Americanadjective
noun
-
a caustic substance.
-
Optics.
adjective
-
capable of burning or corroding by chemical action
caustic soda
-
sarcastic; cutting
a caustic reply
-
of, relating to, or denoting light that is reflected or refracted by a curved surface
noun
-
Also called: caustic surface. a surface that envelops the light rays reflected or refracted by a curved surface
-
Also called: caustic curve. a curve formed by the intersection of a caustic surface with a plane
-
chem a caustic substance, esp an alkali
Other Word Forms
- caustical adjective
- caustically adverb
- causticity noun
- causticly adverb
- causticness noun
- noncaustic adjective
- noncaustically adverb
- overcaustic adjective
- overcaustically adverb
- overcausticity noun
- uncaustic adjective
- uncaustically adverb
Etymology
Origin of caustic
1350–1400; Middle English < Latin causticus < Greek kaustikós burning, caustic, equivalent to kaust ( ós ) burnt (verbal adjective of kaíein to burn) + -ikos -ic
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The federal investigators encountered puddles of crude oil on the facility grounds, as well as caustic fumes emanating from the facility, resulting in violations for air quality and other environmental infractions.
From Los Angeles Times • Feb. 14, 2026
I have enjoyed the caustic verve of this Claude.ai promotional campaign, which seems to be heading off the inevitable swoon of the A.I. revolution before it firmly takes hold.
From Slate • Feb. 8, 2026
Over the past 14 years, Warsh has been a consistent critic of the Fed, often in caustic terms.
From MarketWatch • Jan. 31, 2026
Several people who have spoken with Warsh said they have been taken aback by what they view as the caustic nature of his criticisms of Fed leaders.
From The Wall Street Journal • Jan. 30, 2026
In the past when he walked out like that and sat looking over the country lying in just the faintest visible shape where the lost moon tracked the caustic waste he’d sometimes see a light.
From "The Road" by Cormac McCarthy
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
