poisonous

Etymology

It is formed from English poison + -ous.^[2][3][4][5] Poison is from Old French poison (“a drink”), from Latin pōtiō (“a drinking”).^[4]

Earliest recorded meaning

Containing poison or having its properties; venomous: 1425, in the poem When Crist was Risen.^[2] Other dictionaries date the word later: the 1570s in Etymonline,^[4] the mid-16th century in the Shorter Oxford,^[3] and 1565–75 in Dictionary.com.^[5]

Semantic evolution

The figurative sense, morally corrupting or malicious, followed in 1555.^[2][3] Etymonline lists rivals that did not last: poisonful (1550s), poisonsome and poisony (1590s); earlier, poisoned was used in this sense, from the late 15th century.^[4] Johnson (1755) defined it as venomous, quoting Shakespeare's Coriolanus.^[6] Since 1906 it has been used colloquially for something merely unpleasant or nasty.^[2][3]

Timeline

• 1425 – containing poison, venomous.^[2]
• 1555 – morally destructive or corrupting, malicious.^[2]
• 1570s – first date in Etymonline.^[4]
• 1906 – colloquial, unpleasant, nasty.^[2]

Meanings

Adjective

1. Containing poison or having its effects; toxic: Some of the mushrooms in these woods are poisonous.^[7][8][2]
2. Able to kill or injure with poison; venomous: a poisonous spider.^[7][8]
3. Morally harmful or malicious: a poisonous rumour.^[7][2][3]
4. (colloquial) Very unpleasant; nasty.^[2][3]

Word family

• poisonously
• poisonousness
• nonpoisonous
• unpoisonous

Related words

• poison
• potion

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
4. ^ a b c d e Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
5. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
6. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
7. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins
8. ^ a b Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster