jejune
adjective /dʒɪˈdʒuːn/
  /dʒɪˈdʒuːn/
(formal)- too simple synonym naive
 - (of a speech, etc.) not interesting
 
Word Originearly 17th cent.: from Latin jejunus ‘fasting, barren’. The original sense was ‘without food’, hence ‘not intellectually nourishing’.