- in or towards the higher part of a stream; against the current
- (in the oil industry) of or for any of the stages prior to oil production, such as exploration or research
WordReference Random House Learner's Dictionary of American English © 2026
up•stream /ˈʌpˈstrim/USA pronunciation
adv.
adj.
WordReference Random House Unabridged Dictionary of American English © 2026- toward or in the higher part of a stream;
against the current.
adj.
- directed or located upstream.
up•stream
(up′strēm′),USA pronunciation adv.
adj.
- toward or in the higher part of a stream;
against the current.
adj.
- directed upstream;
situated upstream:an upstream journey; an upstream hideout. - Business[Com.]of or pertaining to the early stages in the operations of a business or industry, as exploration and production in the oil business (opposed to downstream).
- Geneticsagainst or opposite to the direction of transcription, translation, or synthesis of a DNA, RNA, or protein molecule.
- up- + stream 1675–85
Collins Concise English Dictionary © HarperCollins Publishers::
upstream /ˈʌpˈstriːm/ adv , adj
'upstream' also found in these entries (note: many are not synonyms or translations):
above
- Aswan High Dam
- downstream
- paddle
- run
- salmon ladder
- upper
- Volta
- barbed tributary
- bushwhack
- cutwater
- fish ladder
- head gate
- ice apron
- mitergate
- Pitot tube