underused

adj

1. (not-comparable)Used less than normal or desirable.

   “This is reflected in the sterling work of community rail, mobilising volunteers and stakeholders to revitalise underused station buildings and engage with their local community.”

   “Underused neuronal pathways are pruned back, as are underused patches of mycelium.”

verb

1. (form-of, participle, past)simple past and past participle of underuse