Pronunciation: (up'strēm'),[key] —adv. toward or in the higher part of a stream; against the current.
—adj. 1. directed upstream; situated upstream: an upstream journey; an upstream hideout. 2. 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).
3. against or opposite to the direction of transcription, translation, or synthesis of a DNA, RNA, or protein molecule.