jejune - uninteresting
Something, such as an idea, that is described as ‘jejune’ is thought to be banal and uninteresting, typically due to being very basic or unsophisticated. This formal word is, therefore, used to express disapproval, but in a nicer way than simply calling something stupid or childish.
I don’t think I can sit through another of the professor’s jejune lectures. I'm probably going to head home instead.
In the meeting, John made a number of jejune generalizations about other members of staff, essentially accusing them all of not pulling their weight.
I really didn’t enjoy that novel at all. The prose was far too clumsy and jejune for my tastes.