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

If hard water is your frustration, the answer starts upstream of the showerhead. — Ryan Brennan, Miami Herald, 16 Sep. 2026

Tucker and her husband, Jimmy, lived about four and a half miles upstream from Jackson Island. — Brandi D. Addison, USA Today, 15 Sep. 2026

Others, like salmon, return upstream via Metro-North or the Long Island Rail Road to the suburban headwaters in which they were born, in order to spawn. — Christopher Bonanos, Curbed, 2 Sep. 2026

Erosion control was in order in the burn scars upstream of Roaring Springs, the entire park’s only source of drinking water. — Shi En Kim, AZCentral.com, 24 Aug. 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