specious

This is one of those deliciously sneaky words that starts out looking almost innocent. In Latin, species meant 'appearance' or 'beauty,' the same family that gives us specimen and spectacle — words that all put the eyes front and center. Then Latin made speciosus, something flashy, well-groomed, almost too polished for comfort. By the late 1500s English was happy to borrow the word, but by the 1610s it had noticed the catch: a thing can look noble and still be rotten underneath. That’s why a specious argument is the verbal equivalent of a gilded apple — shiny on the shelf, disappointing when you bite it.