Countertypes are different versions or varieties of something. The antonyms for this term could be one of the following - identical, same, clone, copy, or replicate. These words suggest that there is no variation or difference between two entities. On the other hand, if you're looking for something that is the complete opposite of a countertype, some antonyms could be unique, distinct, original, individual, or singular. These words indicate that an object or idea is one-of-a-kind, and has no similar counterpart. Therefore, understanding both the synonyms and antonyms of a term can help to broaden one's vocabulary and language skills.