Finnish word murhaaja comes from Finnish murhata ((transitive) To murder.), Finnish -ja (Forms agent nouns, especially human ones; -er.)

Detailed word origin of murhaaja

Dictionary entry	Language	Definition
murhata	Finnish (fin)	(transitive) To murder.
-ja	Finnish (fin)	Forms agent nouns, especially human ones; -er.
murhaaja	Finnish (fin)	A murderer; (when sure that perpetrator is female but not necessarily saying it) a murderess.

Words with the same origin as murhaaja