roughage
noun /ˈrʌfɪdʒ/
  /ˈrʌfɪdʒ/
[uncountable]- the part of food that helps to keep a person healthy by keeping the bowels working and moving other food quickly through the body食物中的粗纤维 - Fruit and vegetables are important sources of roughage.水果和蔬菜是粗粮的重要来源。 
 
- Fruit and vegetables are important sources of roughage.