What is "arachidonic acid"

n. (context fatty acid English) A long-chain polyunsaturated fatty acid, having 20 carbon atoms and four double bonds, found in animal fats; it is essential for human nutrition, being a precursor to the production of prostaglandins.

Arachidonic acid (AA, sometimes ARA) is a polyunsaturated omega-6 fatty acid 20:4(ω-6). It is structurally related to the saturated arachidic acid found in peanut oil (L. arachis – peanut).