1. Any of a group of chemically diverse proteins that appears microscopically homogeneous, but is composed of linearnonbranching aggregated fibrils arranged in sheets when seen under the electron microscope; it stains dark brown withiodine, produces a characteristic green color in polarized light after staining with Congo red, is metachromatic with eithermethyl violet (pink-red) or crystal violet (purple-red), and fluoresces yellow after thioflavine T staining; amyloid occurscharacteristically as pathologic extracellular deposits (amyloidosis), especially in association with reticuloendothelialtissue; the chemical nature of the proteinaceous fibrils is dependent upon the underlying disease process.2. Resembling or containing starch.