POZZOLAN is validvalid

a finely divided material used to make cement [n POZZOLANS]

77,909 of 196,601 in NWL2023·also valid in CSW24

(Italian) volcanic ashes from Pozzuoli, in Italy, used in the manufacture of a kind of mortar which hardens under water, also POZZOLANA, POZZUOLANA, PUZZOLANA [n -S]