Mammoth Uncensored Word List:
20 words ending with hs, 16 letters long

astrophotographs chemolithotrophs ducentilliardths duocentillionths duodecilliardths electromyographs macrophotographs microphonographs microphotographs microradiographs nongentillionths octodecillionths photolithographs photomicrographs rechromatographs sescentillionths trecentillionths tredecilliardths trigintillionths vigintilliardths