мыльная

In a sentence

• Я использую мыльную воду для уборки.

  I use soapy water for cleaning.

  Here, 'мыльная' ('soapy') is an adjective describing the water, indicating it contains or is related to soap.

• Рабочие аккуратно обработали мыльную поверхность.

  Workers carefully treated the soapy surface.

  In this sentence, 'мыльная' ('soapy') is an adjective connected to 'surface', suggesting the surface is slick or covered with soap.

• Она предпочитает только мыльную оперу по телевидению.

  She only prefers soap operas on television.

  Here, 'мыльная' ('soap') is part of the compound noun 'мыльная опера' ('soap opera'), used figuratively to refer to serialized shows, originating from the soap advertisements during such shows.