Mammoth Uncensored Word List:
67 words ending with ts, 17 letters long

accommodationists anesthesiologists anthropomorphists antievolutionists antireductionists chromaphiloblasts collaborationists confrontationists contrabassoonists controversialists countercomplaints counterculturists counterinsurgents counterstatements counterterrorists cytotechnologists demonstrationists desegregationists disestablishments disfranchisements electrophysicists electrotherapists embourgeoisements environmentalists histopathologists horticulturalists hyperdevelopments immunogeneticists institutionalists internationalists introspectionists malapportionments mechanotherapists microenvironments multiculturalists mycotoxicologists neuropathologists neuroradiologists nonentertainments nonestablishments nonexhibitionists nonreappointments nullificationists otolaryngologists palaeoxylologists paleoenvironments paleolimnologists paleoneurologists paleopathologists parapsychologists photogrammetrists photoluminescents phytolithologists phytopathologists premillennialists psychooncologists psychopannychists reincarnationists superheavyweights supranationalists thermodynamicists transcriptionists ultranationalists unacknowledgments underachievements underdevelopments undernourishments