Mammoth Uncensored Word List:
30 words ending with ts, 18 letters long

biostratigraphists congregationalists constitutionalists conversationalists counterdeployments countergovernments counterstrategists deconstructionists ethnomusicologists hydrometallurgists immunopathologists immunosuppressants lepidopterologists lumpenproletariats neurophysiologists neuropsychiatrists neuropsychologists neurotoxicologists nonanthropologists noncooperationists nontraditionalists orthopsychiatrists overembellishments postimpressionists postmillennialists preacknowledgments psychopathologists reconstructionists redistributionists transcendentalists