Mis-begotten is an adjective used to describe something that is illegitimate or poorly conceived. It is a negative term that implies something is faulty or flawed, either in production or in nature. Antonyms for mis-begotten would include terms such as legitimate, rightful, authentic, genuine, or valid, which denote something that is legal, correct, and trustworthy. These antonyms suggest that the thing in question is not false or fraudulent, rather it is true and real. Other antonyms could include words such as well-conceived, well-made, well-formed or well-crafted. Each of these suggests something that is of high quality, skillfully fashioned, thoughtfully prepared or well-executed.