Entry 1 sense Webster, 1913 Peristoma /(pē̇*rĭs"tō̇*mȧ)/ · Pe·ris·to·ma · IPA 01 n. Same as Peristome. pl. Peristomata ((pĕr`ĭ*stŏm"ȧ*tȧ)) 1. Same as Peristome. See: Peristome