Reflux

Part of speech: noun, verb

Pronunciation: /ˈɹiː.flʌks/

Definitions

1. The backward flow of liquid or gas in a direction opposite to the normal or intended movement
2. The phenomenon where a fluid moves in the reverse direction, often leading to confusion or discomfort in various systems
3. The backward flow of a substance through a passage, which may cause discomfort or disruption in the normal operation of systems involved

Etymology: "Reflux" comes from Latin "refluere," built from "re-," meaning back, and "fluere," meaning to flow. That same root gives English "fluid," "fluent," and "flux," so a reflux is literally a flowing back. The Latin past participle "refluxus" carried the sense of an ebbing tide or a backward current, and English kept that meaning. As a verb, "reflux" still means to flow back in this way. Its most familiar modern use is medical, describing stomach contents moving upward toward the throat. The underlying image has not changed: something that has moved forward is pushed back along the path it came.

Synonyms: backflow, regurgitation