roughage

noun3

1. •
   Substances, generally of plant origin, consisting mostly of complex carbohydrates which are undigested when eaten by humans, and which therefore help the passage of food and waste through the alimentary tract; dietary fibre.

   • I keep telling her not to eat all that roughage for brekky; prunes, bran, and baked beans. — 1995
2. •
   Coarse or rough plant material such as hay and silage used as animal fodder.
3. •
   Originally (archaic), garbage, rubbish, or waste; later (agriculture) the portions of a crop which are discarded, such as husks, stalks, etc.; also, agricultural waste such as weeds.