Predeveloped means to have been developed or improved earlier, therefore antonyms for this word would be underdeveloped, undeveloped, backward, primitive, outdated, or raw. These words connote a state of something that has not yet been developed, improved, or matured. For example, an underdeveloped country is one that lacks modern infrastructure, while an outdated technology is one that has been surpassed by newer models. Conversely, predeveloped suggests something that has seen progress or advancement, indicating a state further along than the other antonyms. Antonyms for predeveloped represent the starting point, whereas predeveloped is the point beyond.