Surfactant

[Mark Zuckerberg]

n- a molecule containing both hydrophilic (water loving, polar) and hydrophobic (water hating, nonpolar) parts, thus enabling the mixture of two generally imiscible (noncompatable) solvents such as oil and water.

[Zipporah Schumaker]

a substance that reduces the surface tension of a liquid (= the natural force existing in a liquid that holds its surface together) :