Pronunciation: (doun'strēm'), [key]
with or in the direction of the current of a stream.
1. of or pertaining to the latter part of a process or system.
2. Genetics.with or in the direction of transcription, translation, or synthesis of a DNA, RNA, or protein molecule.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.