The antonyms for the word kingsize are varied and can be based on context. When it comes to a bed or room, antonyms include twin, single, small, or modest. For clothing, antonyms could be small, little, or petite. In terms of food or drink, antonyms for kingsize could be small, regular, or medium. In general, antonyms for kingsize imply something that is smaller, modest, or regular in size. Regardless of the context, having a variety of antonyms is crucial to understanding the different shades of meaning associated with a particular word.