frivolous

An action or behavior that's frivolous is silly and not very important.

When we call something or someone frivolous, it usually means they're wasting time or energy on something ridiculous. For example, if someone spends their whole day playing video games instead of doing chores, you might say their day was a bit frivolous. You could also use the word to describe a person who's always making jokes and never takes anything seriously - that person is being a bit too frivolous for some people's taste.