The antonyms for the word "most pocketsized" are "bulky," "large," "oversized," "jumbo," and "hefty." These antonyms indicate something that is significantly larger than the typical size of a pocket-sized item. Such items may be difficult to carry around or store in a pocket, purse, or bag. Bulky objects may include furniture, appliances, or heavy equipment, whereas oversized and jumbo objects may include clothing, sports equipment, or toys. Hefty objects may include items that are particularly heavy or bulky, such as books or musical instruments. Therefore, by using these antonyms, one can describe an object as being the opposite of being "most pocketsized.