1. (

• fallacious ,
• unsound

) containing or based on a fallacy; "fallacious reasoning"; "an unsound argument" ;

2. (

• deceitful ,
• fallacious ,
• fraudulent

) intended to deceive; "deceitful advertising"; "fallacious testimony"; "smooth, shining, and deceitful as thin ice" - S.T.Coleridge; "a fraudulent scheme to escape paying taxes" ;

3. (

• fallacious

) based on an incorrect or misleading notion or information; "fallacious hope" ;