surfactant

/səɹˈfæktənt/

IPA: /S ER0 F AE1 K T AH0 N T/

noun
  1. 1

    A surface active agent, or wetting agent, capable of reducing the surface tension of a liquid; typically organic compounds having a hydrophilic "head" and a hydrophobic "tail".

  2. 2

    A lipoprotein in the tissues of the lung that reduces surface tension and permits more efficient gas transport.

Source: https://en.wiktionary.org/wiki/surfactant