poisonous
/ˈpɔɪzənəs/adjective
poisonous is spelled P-O-I-S-O-N-O-U-S: 9 letters and 3 syllables. It appears 3.7 times per million words in written English, the 13,496th most frequent word form (wordfreq, 2021 data). As an adjective, poisonous means “Containing sufficient poison to be dangerous to touch or ingest” (English Wiktionary, September 2026).
How many letters and syllables are in poisonous?
| Letters | 9: P-O-I-S-O-N-O-U-S |
|---|---|
| Syllables | 3 (from its American pronunciation) |
| In writing | 3.7 times per million words; the 13,496th 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 poisonous?
Poisonous appears 3.7 times per million words in written English, the 13,496th 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 poisonous?
- /ˈpɔɪzənəs/
- /ˈpɔɪznəs/
Poisonous has 3 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: LL-Q1860_(eng)-Back_ache-poisonous.wav, Wikimedia Commons (author and licence on each file's page).
Forms of poisonous
- more poisonous comparative
- most poisonous superlative
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does poisonous mean?
The meanings the English Wiktionary records, quoted as written there (source below).
adjective
- 1
Containing sufficient poison to be dangerous to touch or ingest.
While highly poisonous to dogs, this substance is completely harmless if ingested by humans.
- 2
proscribedOf an animal such as a snake or spider, or parts of its body: producing a toxin intended for defensive or offensive use which is usually injected into an enemy or prey by biting or stinging; hence, of a bite or sting: injecting poison.
Poisonous snakes should only be handled by experienced professionals.
- 3
Negative, harmful.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Poisonous in Spanish, French, German and Portuguese
| Language | Words |
|---|---|
| French | vénéneux, toxique |
| German | giftig , toxisch |
| Portuguese | tóxico, venenoso |
| Spanish | ponzoñoso |
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 poisonous come from?
From Middle English poisounous, poysonouse. By surface analysis, poison + -ous.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).