a vague and misused term, subject to misinterpretation. Usually implies that levels of contaminants (salts, metals, etc.) have been reduced but not completely eliminated. The NSF website defines it as "A type of water which has been produced by distillation, deionization, reverse osmosis, or other suitable processes. Purified water may also be referred to as 'demineralized water.' It meets the definition of 'purified water' in the United State Pharmacopoeia."