any of a group of synthetic, organic, liquid or water-soluble cleaning agents that, unlike soap, are not prepared from fats and oils, are not inactivated by hard water, and have wetting-agent and emulsifying-agent properties.
a similar substance that is oil-soluble and capable of holding insoluble foreign matter in suspension, used in lubricating oils, dry-cleaning preparations, etc.
any cleansing agent, including soap. Cf. anionic detergent, cationic detergent, synthetic detergent.