Definition of paroxysmist in US English:

paroxysmist

noun

Geology
rare, historical
  • A person who holds or advocates the theory of catastrophism; a catastrophist.

Origin

Mid 19th century; earliest use found in John Lubbock (1834–1913), banker, politician, and scientific writer. From paroxysm + -ist.

Pronunciation

paroxysmist

/ˌparəkˈsɪzmɪst/