sedimentary

Etymology

It is formed from English sediment + -ary;^{[2][3][4][5][6]} the OED compares French sédimentaire.^[2] Sediment is from French sédiment and Latin sedimentum (“a settling, sinking down”),^[3][2][7][8] from sedeō (“to sit, settle”),^[3][2][7] from Proto-Indo-European *sed- (“to sit”).^[3] Klein relates it to sedentary.^[8]

Earliest recorded meaning

Of the nature of dregs or sediment, settled out of a liquid by gravity: 1760, according to Etymonline.^[3] The OED's first record of this sense is from 1846,^[2] and its earliest quotation for the word is the geological sense, in Charles Lyell's Principles of Geology (1830);^[2] Merriam-Webster also gives 1830^[4] and Dictionary.com 1820–30.^[6]

Semantic evolution

In geology the word describes rock formed from material laid down by water, a use Etymonline finds by 1814^[3] and the OED from 1830, in Lyell.^[2] As a noun, a sedimentary formation or deposit, it is recorded from 1878.^[2][4] An older adjective, sedimental, pertaining to dregs, is recorded from about 1600.^[3]

Timeline

• 1760 – of the nature of dregs or sediment.^[3] The OED's first record of this sense is from 1846.^[2]
• 1814 – in geology, of rock formed by deposition from water.^[3] The OED's first record of the geological sense is from 1830.^[2]
• 1878 – noun, a sedimentary formation or deposit.^[2]

Meanings

Adjective

1. (geology) Of rock: formed by the build-up and hardening of mineral and organic fragments laid down by water, ice or wind; compare igneous and metamorphic: Sandstone and shale are common sedimentary rocks.^[9][4][2]
2. Of, relating to, or containing sediment: sedimentary layers on the lake bed.^[9][4][2]

Noun

1. A sedimentary rock, deposit or formation.^[4][2][5]

Related words

• sediment
• sedimentation
• sedentary

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g h i Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
5. ^ a b Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
6. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
7. ^ a b Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
8. ^ a b Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
9. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins