Mammoth Uncensored Word List:
47 words ending with g, 17 letters long

adrenalectomizing chemosynthesizing circumstantiating conventionalising conventionalizing counterblockading dedifferentiating deindustrialising deindustrializing departmentalising departmentalizing dephlogisticating dephosphorylating electrodepositing governmentalizing immunosuppressing intellectualising intellectualizing mischaracterizing nondiscriminating nondistinguishing overcommunicating overorchestrating overproportioning overrationalizing photodissociating photoreactivating photosynthesising photosynthesizing precongratulating prediscriminating professionalising professionalizing radiobroadcasting radiopasteurizing reconceptualizing recontextualizing reindustrializing straightjacketing superspecializing telephotographing totalitarianizing transilluminating ultracentrifuging underrepresenting undifferentiating videoconferencing