from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A surface-active substance.
- n. A substance composed of lipoprotein that is secreted by the alveolar cells of the lung and serves to maintain the stability of pulmonary tissue by reducing the surface tension of fluids that coat the lung.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. 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".
- n. A lipoprotein in the tissues of the lung that reduces surface tension and permits more efficient gas transport.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a chemical agent capable of reducing the surface tension of a liquid in which it is dissolved
surf(ace)-act(ive) + a(ge)nt.(American Heritage® Dictionary of the English Language, Fourth Edition)
surface-active agent (Wiktionary)