'Pozzolana' definitions:

Definition of 'Pozzolana'

From: GCIDE

Pozzuolana \Poz`zu*o*la"na\, Pozzolana \Poz`zo*la"*na\, n. [It.] Volcanic ashes from Pozzuoli, in Italy, used in the manufacture of a kind of mortar which hardens under water. [1913 Webster]