firelock vs flintlock

firelock and flintlock both are nouns.

Word	Noun	Adjective	Verb	Adverb
firelock	Yes	No	No	No
flintlock	Yes	No	No	No

As nouns, firelock and flintlock are synonyms defined as:

firelock and flintlock: a muzzle loader that had a flintlock type of gunlock

firelock (noun)	flintlock (noun)
a muzzle loader that had a flintlock type of gunlock	an obsolete gunlock that has flint embedded in the hammer; the flint makes a spark that ignites the charge
	a muzzle loader that had a flintlock type of gunlock