jabber vs verbalize

jabber is a noun but verbalize is not a noun.

Word	Noun	Adjective	Verb	Adverb
jabber	Yes	No	Yes	No
verbalize	No	No	Yes	No

As verbs, verbalize is a hypernym of jabber; that is, verbalize is a word with a broader meaning than jabber:

Other hypernyms of jabber include mouth, speak, talk, utter, verbalise.

jabber (noun)	verbalize (noun)
rapid and indistinct speech

jabber (verb)	verbalize (verb)
talk in a noisy, excited, or declamatory manner	convert into a verb
	express in speech
	be verbose
	articulate; either verbally or with a cry, shout, or noise