IGM en · NOUN Meanings (abbreviation, alt-of) Abbreviation of InterGalactic Medium. alt of InterGalactic Medium (abbreviation, alt-of, initialism) Initialism of in-game module. alt of in-game module Blood Pitᵀᴹ — an “In-Game Module” (IGM) quest for the Adventures of Renownᵀᴹ Gaming System. 2016, Stephen Gose, Making Multiplayer Online Games, page 268: (abbreviation, alt-of, initialism) Initialism of International Grandmaster alt of International Grandmaster Forms SpellingFeaturesLabelsSource IGMs Number=Plur lexicographic Relateds ECM · ISM · EGM · IPM · ICM