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

Just as Costco and Walmart identified vulnerabilities in food supply chains, and Amazon and Wayfair recognized efficiencies in logistics, Home Depot is moving upstream in drywall, ceilings, and steel framing, categories highly exposed to tariffs and supply shocks. —Brian Delp, Forbes.com, 9 Sep. 2025

The president was likely referring to a $1.15 billion infrastructure project at the Brandon Road Lock and Dam on the Des Plaines River in Joliet, to build the last, multipronged line of defense against silver and bighead carp moving upstream. —Adriana Pérez, Chicago Tribune, 27 Aug. 2025

From the turnoff on U.S. 24 at Homestake Reservoir Road to the dam 10 miles upstream at 10,200 feet, Homestake Creek meanders through a wide wetland teeming with lush shrubbery, wildlife and the occasional lily pond. —John Meyer, Denver Post, 25 Aug. 2025

Beginning in Nolensville, Mill Creek stretches through parts of Williamson and Davidson counties before emptying out in the Cumberland River a few miles upstream from downtown Nashville. —Stuart Dyos, Nashville Tennessean, 14 Aug. 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