upstream

Etymology

It is formed from English up + stream.^{[2][3][4][5][6]}

Earliest recorded meaning

As an adverb, in a direction against the flow of a stream, or higher up along it: 1681, in W. Robertson's Phraseologia Generalis.^[2][5] Etymonline dates it to the 1680s^[4] and Dictionary.com to 1675–85.^[6]

Semantic evolution

The adjective followed in the 19th century: "directed or taking place upstream" in 1826, in J. F. Cooper's Last of the Mohicans, and "situated farther up a stream" from 1838.^[2][4] A rare American use for "difficult, troublesome" is recorded from 1847.^[2] In the oil and gas industries the adjective has been used since 1965 for the stages before the raw material is ready for refining, such as exploration and extraction, and the adverb since 1973;^[2][7] in biology it has meant, since 1977, in the direction opposite to that in which a DNA or RNA sequence is transcribed.^[2][5] In the oil and biology senses it is contrasted with downstream.^[2][7]

Timeline

• 1681 – adverb, against the current, farther up a stream.^[2][5]
• 1826 – adjective, directed or moving upstream.^[2]
• 1838 – adjective, situated farther up a stream.^[2][4]
• 1847 – US, difficult, troublesome (rare).^[2]
• 1891 – as a quasi-noun, a place farther up a stream.^[2]
• 1965 – adjective, of the oil and gas industry before refining.^[2]
• 1973 – adverb, at or towards the source of oil and gas production.^[2]
• 1977 – biology, in the direction opposite to transcription.^[2]

Meanings

Adverb

1. Towards the source of a stream or river; against the current: The salmon swim upstream to spawn.^[7][5][2]
2. In the oil and gas industries, at or towards the stages of exploration and extraction, before refining.^[7][2]
3. In biology, along a DNA or RNA molecule in the direction opposite to that of transcription.^[5][2]

Adjective

1. Situated farther up a stream, or moving against its current: an upstream dam.^[2][7]
2. Relating to the stages of oil and gas production before the raw material is refined: upstream investment.^[7][2]

Related words

• downstream
• stream
• up

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o p q r s t Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ 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 Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
5. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
7. ^ a b c d e f Collins English Dictionary (2023), Glasgow: HarperCollins