The antonym for the word "more advancing" could be "less progressing". This implies slowing down or reaching a plateau in the process of growth or development. It could also mean retreating or regressing, as in a situation where progress has been reversed or lost. Other antonyms for "more advancing" could include adjectives like stagnant, dormant, static, or even declining. Depending on the context, the opposite of "more advancing" could also be described as remaining the same, not changing, or even moving backwards. It's important to consider the context carefully when searching for the antonym of a word to ensure accuracy in communication.