blunder vs verbalise

blunder is a noun but verbalise is not a noun.

Word	Noun	Adjective	Verb	Adverb
blunder	Yes	No	Yes	No
verbalise	No	No	Yes	No

As verbs, verbalise is a hypernym of blunder; that is, verbalise is a word with a broader meaning than blunder:

Other hypernyms of blunder include mouth, speak, talk, utter, verbalize.

blunder (noun)	verbalise (noun)
an embarrassing mistake

blunder (verb)	verbalise (verb)
utter impulsively	convert into a verb
make one's way clumsily or blindly	express in speech
commit a faux pas or a fault or make a serious mistake	be verbose
	articulate; either verbally or with a cry, shout, or noise