Having its affinity satisfied; combined with all it can hold; -- said of certain atoms, radicals, or compounds; thus, methane is a saturated compound. Contrasted with unsaturated.
An organic molecule is described as saturated if it is a closed shell species lacking double or triple bonds; forming a new bond to a saturated molecule requires the cleavage of an existing bond.
Fatty acids have long chains of carbon atoms, each with four bonding places, if all the free bonds are occupied by hydrogen atoms, the acid is said to be saturated. Oils consisting of mainly saturated fatty acids are generally solid at room temperature.