noun

1. a substance used with water to produce suds for washing or cleaning: soaps are usually sodium or potassium salts of fatty acids, produced by the action of an alkali, as caustic soda or potash, on fats or oils
2. any metallic salt of a fatty acid
3. ☆ Slang soap opera
   also soaper soap′er

Etymology: ME sope < OE sape, akin to Ger seife < Gmc *saipo- < IE base *seib-, to trickle, run out > L sebum, tallow

transitive verb