What does "voluminous" mean?

Voluminous: Of or pertaining to volume or volumes. Specifically: -- (a) Consisting of many folds, coils, or convolutions. But ended foul in many a scaly fold, Voluminous and vast. Milton. Over which dusky draperies are hanging, and voluminous curtains have long since fallen. De Quincey. (b) Of great volume, or bulk; large. B. Jonson. (c) Consisting of many volumes or books; as, the collections of Muratori are voluminous. (d) Having written much, or produced many volumes; copious; diffuse; as, a voluminous writer. -- Vo*lu"mi*nous*ly, adv. -- Vo*lu"mi*nous*ness, n.