Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993.
jejune (adj.)
means “lacking interest,” “empty,” “insipid,” as in She wrote jejune plays that bored audiences and critics alike; figuratively it also means “empty” in the sense of “not nutritionally good,” as in She followed a series of jejune diets that undermined her health; and, possibly because of a confusion with French jeune (“young”), it has come also to mean “childish, immature,” as in His humor was unfortunately jejune. Standard English now uses jejune in all these senses, but some commentators object to the “immature” sense. Best advice: stick with the two “empty, insipid” senses.
