<biochemistry> Fatty acid with one or more double bonds. ... (18 Nov 1997) ... 
a fatty acid that contains one or more double bond(s); those with one double bond are called monounsaturated fatty acids, and those with several are called polyunsaturated fatty acids.
Also see fatty acids. When there is one carbon to carbon double bond within the fatty acid chain, the fatty acid is described as being monounsaturated; the occurrence of two or mor e carbon to carbon double bonds in the fatty acid chain will result in a polyunsaturated fatty acid. The double bonds mean that the carbon atoms have fewer hydrogen atom...
Fatty acid with one or more double bonds. See Table L3.
Type: Term Definitions: 1. a fatty acid, the carbon chain of which possesses one or more double or triple bonds (oleic acid, with one double bond in the molecule, and linoleic acid, with two); called unsaturated because it is capable of absorbing additional hydrogen.
[n] - a fatty acid whose carbon chain can absorb additional hydrogen atoms
lipid with hydrocarbon chains containing one or more carbon-carbon double bonds and subsequently fewer than the maximum number of hydrogen atoms per chain
noun a fatty acid whose carbon chain can absorb additional hydrogen atoms