Incogitable, meaning unimaginable or unthinkable, can have several antonyms depending on the context. In terms of something that is believable, possible, or likely, antonyms could include "conceivable," "thinkable," or "imaginable." Alternatively, if the opposite is something that is ordinary, mundane, or commonplace, antonyms might include "predictable," "common," or "familiar." Antonyms can also be found when considering something that is explicitly not incogitable, such as a fact or a concept that is easily understood or known, in which case antonyms could include "known," "familiar," or "comprehensible." Ultimately, the antonym for incogitable will depend on the intended comparison and the specific language being used.