A device, substance, or system that removes minerals from water or other materials.
From 'demineralize' + agent suffix '-er' (one who does or that which does). English regularly adds '-er' to verbs to create nouns for tools or agents performing the action, dating back to Old English patterns.
Water softeners in homes are basically demineralizers—they swap out hard minerals like calcium and magnesium for sodium, which is why some people notice their tap water tastes slightly salty after treatment.
Complete word intelligence in one call. Free tier — 50 lookups/day.