lith·o·phy·sa \ˌ ̷ ̷ ̷ ̷ˈfīsə\noun (plurallithophy·sae \-ˌsē\) Etymology: New Latin, from lith- + Greek physa bubble — more at pustule : a spherulitic cavity often with concentric chambers that is observed in some rhyolitic lavas • lith·o·phy·sal\| ̷ ̷ ̷ ̷| ̷ ̷səl\adjective