pseu·dos·to·ma \süˈdästəmə\noun Etymology: New Latin, from pseud- + stoma 1.: a stigma in serous membrane filled by intercellular substance or otherwise closed 2.: the temporary mouth of a larval echinoderm 3.: the osculum of a sponge • pseu·do·stoma·tous\|südə|stōməd.əs, -täm-\orpseu·dos·to·mous\(ˈ)sü|dästəməs\adjective