fallacious

adjective

1. containing a fallacy; logically unsound: fallacious arguments.
2. deceptive; misleading: fallacious testimony.
3. disappointing; delusive: a fallacious peace.

adjective

1. containing or involving a fallacy; illogical; erroneous
2. tending to mislead
3. delusive or disappointinga fallacious hope

adj.

c.1500, from fallacy (Latin fallacia) + -ous. Related: Fallaciously; fallaciousness.