Pronunciation: (pô-ros'i-tē, pō-, pu-), [key]
—pl. -ties for 2.
1. the state or quality of being porous.
2. Geol., Engin.the ratio, expressed as a percentage, of the volume of the pores or interstices of a substance, as a rock or rock stratum, to the total volume of the mass.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.