assaulter vs lapidator

assaulter and lapidator both are nouns.

Word	Noun	Adjective	Verb	Adverb
assaulter	Yes	No	No	No
lapidator	Yes	No	No	No

As nouns, lapidator is a hyponym of assaulter; that is, lapidator is a word with a more specific, narrower meaning than assaulter:

assaulter: someone who attacks
lapidator: an attacker who pelts the victim with stones (especially with intent to kill)

assaulter (noun)	lapidator (noun)
someone who attacks	an attacker who pelts the victim with stones (especially with intent to kill)