Real Dictionary

polyunsaturated
adjective: Polyunsaturated oils and margarines are made mainly from vegetable fats and are considered healthier than those made from animal fats.

polyunsaturated in American English
containing more than one double or triple bond in the molecule
adjective: of or noting a class of animal or vegetable fats, esp. plant oils, whose molecules consist of carbon chains with many double bonds unsaturated by hydrogen atoms and that are associated with a low cholesterol content of the blood

polyunsaturated in British English
adjective: of or relating to a class of animal and vegetable fats, the molecules of which consist of long carbon chains with many double bonds. Polyunsaturated compounds are less likely to be converted into cholesterol in the body. They are widely used in margarines