Etymograph

English

fissionist

From fission + -ist.

Formed from fission + -ist

Proto-Indo-European *bʰeyd- ‘to split’

…

Proto-Italic *findō ‘to split, cleave’

Latin findō ‘split, divide’

Latin fissiō ‘the act of breaking up’

Latin fissiōnem

English fission

Today it means

noun A scientist who works on nuclear fission.

Language periods are conventional ranges, not dates for this word.

Etymograph / fissionist