psam·mo·ma \saˈmōmə\noun (pluralpsammomas \-ōməz\ ; orpsammoma·ta \-ōməd.ə\) Etymology: New Latin, from psamm- + -oma : a hard fibrous tumor of the meninges of the brain and spinal cord containing calcareous matter • psam·moma·tous\(ˈ)sa|mōməd.əs, -mäm-\adjective