lacking in excitement, taste, or energy
insipid - dull
Somebody or something ‘insipid’ is lacking in interest and flavour and will likely leave you feeling underwhelmed. The word was originally applied solely to tasteless food but has since been adapted to describe people or things that are similarly bland. It is a formal term used exclusively in a disapproving manner.
I had heard great things about that restaurant, but the food was actually quite insipid.
Paul will never make it as a salesperson. He’s much too insipid a character.
The insipidness of the design is holding the product back. We need to go back to the drawing board with it.