Mammoth Uncensored Word List:
26 - 15 letter words starting with ce

ceaselessnesses cenogenetically censurabilities centenarianisms centibecquerels centralisations centralizations centricalnesses centrifugalised centrifugalises centrifugalized centrifugalizes centrifugations centripetalisms centrosymmetric centuplications cephalochordate cephalothoraces cephalothoracic cephalothoraxes cercopithecoids cerebrovascular cerebrovisceral ceremoniousness certificatories cervicographies