underused /ˌʌndəˈjuːzd/ (also under-used)

• 1. 

  ADJ Something useful that is underused is not used as much for people's benefit as it could be. 未充分使用的

  例：

  Currently many schools' sports grounds are grossly underused.

  目前，许多学校的操场都未被充分使用。