The word “frivool” can be rearranged to form the 4-letter word “FROLIC,” which means to play or dance in a carefree or lighthearted manner. The word “frivolous” means lacking seriousness or sense of responsibility, while “frolic” has a more positive connotation of being playful and lighthearted. In a sentence, you could say, “The children frolicked in the park,” or “The frivolists danced the night away.”