Answer:
The antonyms of natural are abnormal, atypical, unusual and uncommon.
Explanation:
Let's start with antonyms, "Antonyms" is a word that is opposite to the another (e.g. Selfish, the antonyms of selfish is selfless.)
Understanding the deeper meaning of natural, it refers to something that is newly discovered, born, or is a native or regular. According to an researcher, natural refers to something that is not artificial or man-made but it's already exist in it's original state as found in nature.
