unsound vs fallacious

unsound and fallacious both are adjectives.

Word	Noun	Adjective	Verb	Adverb
unsound	No	Yes	No	No
fallacious	No	Yes	No	No

As adjectives, unsound and fallacious are synonyms defined as:

unsound (adjective)	fallacious (adjective)
not sound financially	involving deception
not in good condition; damaged or decayed	based on an incorrect or misleading notion or information
suffering from severe mental illness	containing or based on a fallacy
containing or based on a fallacy
physically unsound or diseased
of e.g. advice