sound off vs beef

sound off is not a noun while beef is a noun.

Word	Noun	Adjective	Verb	Adverb
sound off	No	No	Yes	No
beef	Yes	No	Yes	No

As verbs, beef is a hyponym of sound off; that is, beef is a word with a more specific, narrower meaning than sound off:

sound off (noun)	beef (noun)
	cattle that are reared for their meat
	informal terms for objecting
	meat from an adult domestic bovine

sound off (verb)	beef (verb)
express complaints, discontent, displeasure, or unhappiness	complain
express one's opinion openly and without fear or hesitation
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