/up"streem"/ , adv.
1. toward or in the higher part of a stream; against the current.
adj.
2. directed upstream; situated upstream: an upstream journey; an upstream hideout.
3. 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 ).
4. against or opposite to the direction of transcription, translation, or synthesis of a DNA, RNA, or protein molecule.
[ 1675-85; UP- + STREAM ]