An eicosanoid is a lipid consisting of twenty or more carbons. Lipids as molecules are extremely long amphipathic hydrocarbon chains, between two and twenty carbons connected to a COOH or COO- tail. Eicosanoids are the upper range of lipids, pushing the maximum. They can be either saturated or unsaturated. They will generally be solids at room temperature, with a consistancy similar to waxes.