upstream

adverb or adjective

up·​stream ˈəp-ˈstrēm 

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

But in a recent by-election, Nigel Farage’s populist, pro-Trump, Reform Party overturned a Labour majority of nearly 15,000 in Runcorn, a decayed industrial town, 15 miles upstream from Liverpool on the River Mersey. —Stephen Collinson, CNN Money, 7 June 2025

The court’s liberal justices ultimately reached the same conclusion as their conservative counterparts — that the board did not need to consider the environmental impacts of drilling upstream or refining downstream. —Rachel Frazin, The Hill, 29 May 2025

Their raft capsized, plunging them into a violent, raging current just upstream from its most perilous stretch. —Margie Warrell, Forbes.com, 21 May 2025

Suckers were spawning upstream, and the trout kept coming into the pool in schools to feed on the drifting spawn. —Robeson Bailey, Outdoor Life, 11 June 2025

Word History

First Known Use

1681, in the meaning defined at sense 1

Rhymes for upstream

• abeam
• airstream
• bloodstream
• daydream
• downstream
• esteem
• extreme
• grapheme
• hakim
• hornbeam
• lexeme
• mainstream

Kids Definition

upstream

adverb or adjective

up·​stream ˈəp-ˈstrēm 

: at or toward the beginning of a stream : against the current

salmon swimming upstream

Medical Definition

upstream

adverb or adjective

up·​stream ˈəp-ˈstrēm 

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