anionic detergent

:  any of a class of synthetic detergents usually consisting essentially of an alkali metal salt or an ammonium salt of a strong acid containing 12 to 24 carbon atoms together with an inorganic salt (as sodium sulfate) and, for heavy-duty laundering, a builder (as sodium tripolyphosphate):as a :  an alkyl aryl sulfonate (as sodium dodecyl-benzene-sulfonate C₁₂H₂₅C₆H₄SO₃Na) b :  a salt (as sodium lauryl sulfate C₁₂H₂₅SO₄Na) of a sulfated alcohol