surfactant

sur·fac·tant

noun \(ˌ)sər-ˈfak-tənt, ˈsər-ˌ\

Definition of SURFACTANT

: a surface-active substance; specifically : a surface-active lipoprotein mixture which coats the alveoli and which prevents collapse of the lungs by reducing the surface tension of pulmonary fluids

—surfactant adjective