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

Chinook, or king, salmon were spotted Saturday swimming upstream to spawn in the Los Gatos Creek. —Lisa M. Krieger, The Mercury News, 24 Nov. 2024

Two other dams, which aren’t affected by the project, remain farther upstream in Oregon. —Ian James, Los Angeles Times, 19 Oct. 2024

However, there is a problem upstream in the conduction system that may need to be addressed. —Angela Ryan Lee, Verywell Health, 25 Sep. 2024

This last effort to mitigate flooding will affect dozens of communities both upstream and downstream in the Menomonee River watershed for the better, according to Schindler. —Bridget Fogarty, Journal Sentinel, 5 Nov. 2024

Word History

First Known Use

1681, in the meaning defined at sense 1

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