Specious

1. Seemingly well-reasoned, plausible or true, but actually fallacious.Synonyms: fallacious, insincere
2. Employing fallacious but deceptively plausible arguments; deceitful.
3. Having an attractive appearance intended to generate a favorable response deceptively attractive. Synonyms: meretricious, pretextual
4. (obsolete) Beautiful, pleasing to look at.