caustic
/ˈkɔːstɪk/adjective, noun
caustic is spelled C-A-U-S-T-I-C: 7 letters and 2 syllables. It appears about once in every 1 million words in written English, the 30,017th most frequent word form (wordfreq, 2021 data). As an adjective, caustic means “Capable of burning, corroding or destroying organic tissue” (English Wiktionary, September 2026).
How many letters and syllables are in caustic?
| Letters | 7: C-A-U-S-T-I-C |
|---|---|
| Syllables | 2 (from its American pronunciation) |
| In writing | about once in every 1 million words; the 30,017th most frequent word form |
| Wrong spellings searched | none measured in search |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation and the CMU Pronouncing Dictionary; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How common is caustic?
Caustic appears about once in every 1 million words in written English, the 30,017th most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How do you pronounce caustic?
- UK /ˈkɔːstɪk/
- UK /ˈkɒstɪk/
- British /ˈkoːstɪk/
Caustic has 2 syllables (counted from its American pronunciation in the CMU Pronouncing Dictionary).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: En-us-caustic.ogg, Wikimedia Commons (author and licence on each file's page).
Forms of caustic
- more caustic comparative
- most caustic superlative
- caustics plural
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does caustic mean?
The meanings the English Wiktionary records, quoted as written there (source below).
adjective
- 1
Capable of burning, corroding or destroying organic tissue.
- 2
Sharp, bitter, cutting, biting, and sarcastic in a scathing way.
noun
- 1
Any substance or means which, applied to animal or other organic tissue, burns, corrodes, or destroys it by chemical action; an escharotic.
- 2
The envelope of reflected or refracted rays of light for a given surface or object.
- 3
The envelope of reflected or refracted rays for a given curve.
- 4
informalCaustic soda.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Caustic in Spanish, French, German and Portuguese
| Language | Words |
|---|---|
| German | zersetzend, beißend , scharf, bissig, ätzend , Ätzmittel |
| Portuguese | cáustico , cáustica |
| Spanish | cáustico |
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.
Where does caustic come from?
From the Latin causticus (“burning”), from Ancient Greek καυστικός (kaustikós, “burning”), from καυστός (kaustós, “burnt”) + -ικός (-ikós).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).