petrochemical

Etymology

It is formed from English petro- + chemical.^{[2][3][4][5][6]} The OED and Etymonline distinguish two adjectives: the earlier one, about the chemistry of rocks, has petro- in the sense "rock, stone", from Ancient Greek πέτρος (pétros, “stone”) or πέτρα (pétra, “rock”);^[2][3] the later one has petro- taken from petroleum,^[2][3][4] and was formed after petrochemistry.^[2] According to the OED this second petro- is first found in the mid 20th century in this word and in the noun petrochemistry.^[2]

Earliest recorded meaning

Of or relating to the chemistry of rocks: 1913, in a heading in Chemical Abstracts.^[2][3][7]

Semantic evolution

The petroleum sense, the usual one today, appears in 1942 in the Oil & Gas Journal, both as an adjective, of the chemistry of petroleum or of petrochemicals, and as a noun, a chemical compound obtained industrially from petroleum or natural gas.^[2][3][4][5] Dictionary.com, however, dates the petroleum word to 1910–15.^[8] The OED notes that the noun is usually plural and often attributive, as in the petrochemical industry.^[2][5]

Timeline

• 1913 – adjective, relating to the chemistry of rocks.^[2][3][7]
• 1942 – adjective, relating to the chemistry of petroleum; noun, a chemical obtained from petroleum or natural gas.^[2][3][4][5]

Meanings

Noun

1. A chemical compound obtained from petroleum or natural gas, or made from such a substance, such as acetone or ethanol.^[9][5][2]

Adjective

1. Of, relating to or produced from petrochemicals: a petrochemical plant on the coast.^[9][5][2]
2. Of or relating to the chemistry of rocks; petrological.^[5][2]

Word family

• petrochemistry
• petrochemically

Related words

• petroleum
• petro-
• petrous
• chemistry

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c d Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
5. ^ a b c d e f g Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
7. ^ a b Kay, Christian; Roberts, Jane; Samuels, Michael; Wotherspoon, Irené, eds. (2009), Historical Thesaurus of the Oxford English Dictionary, Oxford: Oxford University Press; online edition (2024)
8. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
9. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins