Entry 1 sense Webster, 1913 Semiphlogisticated /(sĕm`ĭ*flō̇*jĭs"tĭ*kā`tĕd)/ · Sem·i·phlo·gis·ti·ca·ted · IPA 01 a. Partially impregnated with phlogiston. 1. Partially impregnated with phlogiston.(Old Chem.) [Obs.]