Volume  n. 1 single book forming part or all of a work. 2 a solid content, bulk. B space occupied by a gas or liquid. C (foll. By of) amount or quantity. 3 strength of sound, loudness. 4 (foll. By of) a moving mass of water etc. B (usu. In pl.) Mass of smoke etc. [latin volumen: related to *voluble, ancient books being in roll form]