Less serious-minded, frivolous, carefree, lighthearted, flippant, playful, humorous, jovial, merry, jocular, jovial, unserious, unserious, unimportant, trivial, superficial. These are some of the antonyms for the word "more serious-minded." When someone is not serious-minded, they tend to be playful, carefree, and lighthearted. It implies that they do not take things seriously and usually have a happy-go-lucky attitude towards life. The opposite of being serious-minded is being unserious or trivial, which means not taking things seriously, lacking a sense of responsibility, and not being committed. Being less serious-minded is not always a bad thing; it can add some much-needed buoyancy to life.