Definition of upstream for English Language Learners
: in the direction opposite to the flow in a stream, river, etc. : toward the source of a stream, river, etc.
UPSTREAM Defined for Kids
Definition of upstream for Students
:at or toward the beginning of a stream
She rowed upstream.
adverb or adjective
Definition of upstream
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.