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

For the first time in more than a century, salmon pushed upstream past where three hydropower dams once stood, reclaiming a stretch of water that had been cut off for more than a century. —Radina Gigova, CNN Money, 27 May 2026

When both technology and human judgment can be deceived at the point of execution, defense must shift upstream into design, process and governance. —Steve Piper, Forbes.com, 26 May 2026

Long-term resilience requires investing upstream in prevention rather than continually paying for failure downstream. —Richard McCathron, Fortune, 25 May 2026

The San Diego County Psychiatric Hospital has also seen significant changes since MCRT teams began working upstream to prevent crises. —Paul Sisson, San Diego Union-Tribune, 18 May 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