Developings is a noun that refers to the process of growth or advancement. There are a few antonyms to this word that convey the opposite meaning. Regression can be a suitable antonym for developing as it implies the process of declining or going backward instead of advancing. Stagnation, which means a lack of growth or progress, can also be an antonym for developing. Another word that can work as an antonym for developing is deterioration, which suggests the process of worsening or decay. Hence, when trying to convey the opposite meaning of developing, the words regression, stagnation, and deterioration can be used as antonyms.