Mammoth Uncensored Word List:
34 words ending with h, 14 letters long

autolithograph autophytograph autoradiograph barometrograph chemoautotroph crystallograph ducentillionth duodecillionth encephalograph farthingsworth grandfatherish halfpennyworth hobbledehoyish microbarograph millinillionth myocardiograph photoautotroph phototelegraph plethysmograph pyrophotograph quadrilliardth quicksilverish quintilliardth radioautograph radiotelegraph roentgenograph sedecilliardth shillingsworth telephotograph tredecillionth uncentillionth undecilliardth vigintillionth xeroradiograph