rabbit on vs jabber

rabbit on is not a noun while jabber is a noun.

Word	Noun	Adjective	Verb	Adverb
rabbit on	No	No	Yes	No
jabber	Yes	No	Yes	No

As verbs, rabbit on and jabber are synonyms defined as:

Other synonyms of rabbit on include mouth off, rant, rave, spout.

rabbit on (noun)	jabber (noun)
	rapid and indistinct speech

rabbit on (verb)	jabber (verb)
talk in a noisy, excited, or declamatory manner	talk in a noisy, excited, or declamatory manner