Wiktionary
sidestream
n. (context chemistry English) A stream of fluid taken from an intermediate point in a process such as distillation
Usage examples of "sidestream".
She inflated it, holding it under the sidestream of water used for rinsing off their suits prior to deconing them.
I go sideways, past and future are a sidestream to me, a path I can never tread.
It sounded like a sidestream tumbling from the upper rocks, to join the main watercourse beneath.
It was cold and dark, a perfect accompaniment to my mood, and the icy wind was flat and lifeless, with only exhaust fumes and the occasional bit of sidestream cigarette smoke to flavor it.