Pronunciation: (vu-lOO'mu-nus),[key] —adj. 1. forming, filling, or writing a large volume or many volumes: a voluminous edition. 2. sufficient to fill a volume or volumes: a voluminous correspondence. 3. of great volume, size, or extent: voluminous flow of lava. 4. of ample size, extent, or fullness: voluminous petticoats. 5. having many coils, convolutions, or windings.