CN gas vs lachrymator

CN gas and lachrymator both are nouns.

Word	Noun	Adjective	Verb	Adverb
CN gas	Yes	No	No	No
lachrymator	Yes	No	No	No

As nouns, lachrymator is a hypernym of CN gas; that is, lachrymator is a word with a broader meaning than CN gas:

CN gas: a tear gas that is weaker than CS gas but lasts longer
lachrymator: a gas that makes the eyes fill with tears but does not damage them; used in dispersing crowds

Other hypernyms of CN gas include lacrimator, tear gas, teargas.

CN gas (noun)	lachrymator (noun)
a tear gas that is weaker than CS gas but lasts longer	a gas that makes the eyes fill with tears but does not damage them; used in dispersing crowds