shellfish

Etymology

It is inherited from Old English scilfisc,^[2][3][4] also sciellfisc,^[5] formed from Old English sciell (“shell”) + fisc (“fish”),^[5][6] the sources of shell and fish.^[5][4] The word fish here keeps its old general sense of any animal living in water.^[6] It corresponds to Old Norse skelfiskr.^[2][3]

Earliest recorded meaning

Any animal living in water and covered by a shell: the first record is in King Ælfred's Old English translation of Boethius.^[2] Etymonline cites the plural scylfiscas,^[6] and Dictionary.com dates the word to before 900.^[4]

Semantic evolution

The meaning has stayed close to the original one, an aquatic animal with a shell, whether a mollusc such as an oyster or a crustacean such as a crab.^[2][3] Johnson (1755) defined it the same way, as a fish with a hard covering, "testaceous, as oysters, or crustaceous, as lobsters".^[7] Since such animals are eaten, modern dictionaries stress their use as food.^[8][3] A figurative use of a person is recorded from 1809, in Malkin's translation of Gil Blas.^[2] In American English the word also names the boxfish.^[5]

Timeline

• before 900 – any aquatic animal with a shell, in Ælfred's Boethius.^[2][4]
• 1809 – figurative, of a person.^[2]

Meanings

Noun

1. An aquatic invertebrate with a shell, such as a mollusc or a crustacean, especially one eaten as food: The restaurant serves mussels, crab and other shellfish.^[8][5][3]
2. A boxfish.^[5]

Word family

• shellfishing
• shellfishery

References

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