sound off vs opine

sound off and opine both are verbs.

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

As verbs, sound off and opine are synonyms defined as:

sound off and opine: express one's opinion openly and without fear or hesitation

Other synonyms of sound off include animadvert, speak out, speak up.

sound off (verb)	opine (verb)
express complaints, discontent, displeasure, or unhappiness	expect, believe, or suppose
express one's opinion openly and without fear or hesitation	express one's opinion openly and without fear or hesitation
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