Discolourer

Part of speech: noun

Definitions

1. An agent or substance that removes, alters, or darkens the natural color of something
2. Anything that causes a surface or material to lose its original hue or become stained
3. Something that produces an unwanted change in the color or appearance of an object or substance

Etymology: "Discolourer" is a plain formation: the verb "discolour" with the agent suffix "-er," meaning one that performs the action, so a discolourer is whatever discolours. The verb "discolour" itself comes from "dis-," a prefix expressing reversal or removal, joined to "colour," which reaches English from Latin "color." Together the parts give a sense of taking colour away or changing it from its original hue. The word is built entirely from English elements, so there is no foreign borrowing to trace. Its meaning, a substance that stains or alters the colour of something, follows directly from the verb's sense of spoiling or changing a thing's natural hue.