From Longman Dictionary of Contemporary Englishsoap powderˈsoap ˌpowder noun [countable, uncountable] British English DHCa powder that is made from soap and other chemicals, used for washing clothes SYN detergent
Examples from the Corpus
soap powder• She's shown us the label so we can recognize the packaged news story like it was a familiar soap powder.• The few shoppers who are searching for soap powder feel rather awkward.• To make soap powder, a liquid is blown through a nozzle.• Some people find a change of soap powder can help, especially a move away from a biological powder.• Kausmann is not a fetishist and is much more interested in the couple's relationship than in the efficiency of soap powder. 