volcanist

Etymology tree
Doric Greek Ϝέλχανος (Wélkhanos)der.?
Latin Vulcānusbor.
Italian Vulcano
Italian vulcanobor.
English volcano
Proto-Indo-European *-id-
Proto-Indo-European *-yéti
Proto-Indo-European *-idyéti
Proto-Hellenic *-íďďō
Ancient Greek -ῐ́ζω (-ĭ́zō)
Proto-Hellenic *-tās
Ancient Greek -τής (-tḗs)
Ancient Greek -ῐστής (-ĭstḗs)bor.
Latin -istader.
Old French -istebor.
Middle English -ist
English -ist
English volcanist
From volcano + -ist.