Seriousminded individuals are usually characterized as being thoughtful, composed, and responsible. However, sometimes it is nice to let loose, lighten up and take things less seriously. Antonyms for seriousminded could be "playful," "carefree," "flippant," and "irresponsible." These individuals are known for their lightheartedness, humor, and the ability to add a touch of fun to any situation. Such individuals typically don't take life too seriously, and instead, choose to see the brighter and more amusing side of things. While seriousminded people can sometimes appear a little stiff, those on the opposite end of the spectrum exude energy and positivity.