n. & v.
n. (in full pumice-stone) 1 a light porous volcanic rock often used as an abrasive in cleaning or polishing substances. 2 a piece of this used for removing hard skin etc.
v.tr. rub or clean with a pumice. pumiceous adj.
[ ME f. OF pomis f. L pumex pumicis (dial. pom-): cf. POUNCE(2) ]