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

Between stops, stroll along Creek Street and watch salmon push upstream through the heart of downtown. —Josh Rivera, USA Today, 13 May 2026

This would open the door for copper-nickel mining just upstream from the Boundary Waters Canoe Area Wilderness. —Beret Leone, CBS News, 16 Apr. 2026

The Sheriff’s Office said investigators determined the 25-foot DCB Performance Marine Mach 26 catamaran was traveling upstream on the Colorado at a high speed at the time of the crash. —Nicole Buss, Sacbee.com, 8 Apr. 2026

Meanwhile, the push for efficiency moves upstream to the supply chain as Cascale launches a strategic framework to help Asia-Pacific manufacturers move beyond fragmented regulatory hurdles. —Arthur Zaczkiewicz, Footwear News, 2 Apr. 2026

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