(DICTIONARY.COM)

Definition for jejune

1. without interest orsignificance; dull; insipid: ajejune novel.
2. juvenile; immature; childish:jejune behavior.
3. lacking knowledge orexperience; uninformed:jejune attempts to design ahouse.

Citations

The first two are painfully jejune, of course, the wayTom Sawyer is jejune when compared to HuckleberryFinn, but the last one—although no Huck Finn—does show growth.”Stephen King, Finders Keepers, 2015

Origin

Jejune comes from the Latin word jējūnus meaning“empty, poor, mean.”

Source: tumescent – Word of The Day | Dictionary.com