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

The Highland Lakes are a chain of lakes created by a series of flood-control and hydroelectric dams along the Colorado River, upstream from Austin. —Powered By, Austin American Statesman, 7 July 2025

This is odd because the obvious way to attack a crossing like this would be to land upstream and let the current carry it into place (like the floating bridge-busting bombs used in the Caroline Moon operation in Vietnam). —David Hambling, Forbes.com, 4 July 2025

Gravity took the boats toward the Chesapeake Bay, but mules walked along the bank on a tow path, pulling the boats and the loads back upstream. —Diana Lambdin Meyer, USA Today, 28 June 2025

Clear visuals of illicit devices will help local teams pull contraband from shelves and trace it upstream. —Edgar Domenech, Sun Sentinel, 18 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