The term 'verb form used as an adjective' is referring to a participle. A participle is a verb form that can be used as an adjective. It is usually formed by adding '-ing' or '-ed' to the end of a verb. For example, the verb 'WALK' can become the participle 'walking' or 'walked'. When used as an adjective, participles can describe the state or condition of a noun. For example, 'the walking man' or 'the walked path'.