Dietary fibers are the inigestible portion of plant foods that move food through the digestive system, absorbing water and easing defecation. Dietary fiber consists of non-starch polysaccharides such as cellulose and many other plant components such as dextrins, inulin, lignin, waxes, chitins, pectins, beta-glucans and oligosaccharides. The term "fiber" is somewhat of a misnomer, since many of the so-called dietary fibers are not fibers at all. The term has largely taken over the role of the older term "roughage".