adverb or adjective
up·​stream | \ ˈəp-ˈstrēm How to pronounce upstream (audio) \

Definition of upstream

1 : in the direction opposite to the flow of a stream
2 : in or to a position within the production stream closer to manufacturing processes make most of its money upstream, selling cheap crude … to refineries— John Quirt
3 biochemistry : toward the beginning of a series of cellular processes : preceding a linked molecular event occurring in a sequence Many signaling pathways possess intrinsic negative feedback by which a downstream event in a pathway turns off an upstream event.— Harvey Lodish et al.

Examples of upstream in a Sentence

Recent Examples on the Web Some trout have moved upstream, where anglers are having some success fishing the deeper pools with small black hair jigs tipped with maggots, waxworms, minnows and pieces of nightcrawler under a stick float. cleveland, "Tournament anglers catch plenty, but few big walleye: NE Ohio fishing report for weekend of Oct. 16-18," 15 Oct. 2020 The Snellings’ boat, pushed upstream by long poles, became stuck in some trees. Curt Brown, Star Tribune, "Abigail Hunt Snelling Chapman was more than a helpmate at the early years of the fort bearing her name," 19 Sep. 2020 Station yourself upstream and slightly to one side of a rising fish. Popular Science, "A beginner’s guide to catching trout—even in autumn," 26 Oct. 2020 Helping interpret or even write those rules upstream, though, is just as important as defending against their effects. Kate Aronoff, The New Republic, "This Supreme Court Was Designed to Kill Climate Policies," 14 Oct. 2020 That’s because the river was historically so contaminated by raw sewage and industrial waste — before modern wastewater treatment — that engineers had to look upstream for a safe place to install their pumps. Eric Roper, Star Tribune, "How do cities make Mississippi River water safe to drink?," 9 Oct. 2020 The study focuses on the lower sections of Clear Creek from just upstream of Dixie Farm Road to Galveston Bay and the entirety of Dickinson Bayou. Carissa Lamkahouan, Houston Chronicle, "Multiple efforts reflect Friendswood focus on flood control," 6 Oct. 2020 Florida alleges that Georgia farmers upstream along the Flint River used too much of its water for irrigation during a 2012 drought, tanking the Apalachicola Bay’s once-flourishing oyster industry. al, "Supreme Court diving into Georgia-Florida water wars," 7 Oct. 2020 Without full cooperation from the states upstream, the bay’s water quality will remain substandard, the lawsuit asserts. Washington Post, "Three states and D.C. sue EPA, saying the agency failed to enforce plan to reduce Chesapeake Bay pollution," 10 Sep. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'upstream.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of upstream

1681, in the meaning defined at sense 1

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Time Traveler for upstream

Time Traveler

The first known use of upstream was in 1681

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Statistics for upstream

Last Updated

18 Nov 2020

Cite this Entry

“Upstream.” Dictionary, Merriam-Webster, Accessed 30 Nov. 2020.

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More Definitions for upstream


How to pronounce upstream (audio)

English Language Learners Definition of upstream

: in the direction opposite to the flow in a stream, river, etc. : toward the source of a stream, river, etc.


up·​stream | \ ˈəp-ˈstrēm How to pronounce upstream (audio) \

Kids Definition of upstream

: at or toward the beginning of a stream She rowed upstream.


adverb or adjective
up·​stream | \ ˈəp-ˈstrēm How to pronounce upstream (audio) \

Medical Definition of upstream

1 : in a direction along a molecule of DNA or RNA opposite to that in which transcription and translation take place and toward the end having a phosphate group attached to the position labeled 5′ in the terminal nucleotide … stretches of DNA upstream of genes—are known as promoters.— Matt Ridley, Time — compare downstream sense 1
2 : toward the beginning of series of cellular processes : preceding a linked molecular event occurring in a sequence It's equally important to focus on additional mechanisms that are upstream of amyloid formation and mechanisms downstream that are involved in the actual degenerative processes within neurons.— Marc Tessier-Lavigne, quoted in Science

More from Merriam-Webster on upstream

Nglish: Translation of upstream for Spanish Speakers

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