Kidstuff, a term commonly used to refer to things or activities appropriate for children, has several antonyms that denote the opposite. Adult-oriented, grown-up, and mature are all terms that describe things that are intended for an older or more experienced audience. Similarly, sophisticated, refined, and highbrow are antonyms that suggest a level of intellectual or aesthetic complexity that may be inaccessible to children. Meanwhile, serious, sober, and somber are words that connote a gravity or weightiness that is far from the playful or whimsical nature of kidstuff. Finally, uninteresting, tedious, and dull all suggest a lack of excitement or stimulation, words that starkly contrast with the vibrant and lively nature of activities for children.