unserious
/ʌnˈsɪriəs/
adjective
- Not serious; lacking importance, depth, or sincerity; frivolous or playful.
- The meeting was surprisingly unserious, with everyone joking around instead of discussing the budget.
- The movie is a light, unserious comedy perfect for a lazy afternoon.
- She gave an unserious answer to the interview question, which cost her the job.