blunder vs speak

blunder is a noun but speak is not a noun.

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

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

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

blunder (noun)	speak (noun)
an embarrassing mistake

blunder (verb)	speak (verb)
utter impulsively	express in speech
make one's way clumsily or blindly	exchange thoughts; talk with
commit a faux pas or a fault or make a serious mistake	use language
	give a speech to
	make a characteristic or natural sound