What is the definition of the prefix for amoral

The definition of amoral is lacking a moral sense; unconcerned with the rightness or wrongness of something.

the meaning of the prefix "a" is simply making the word negative or opposite - lacking something. for example, moral is positive but when you add the prefix "a" it means that you lack morals, it becomes negative and the opposite of moral

Having or showing no concern about whether behavior is morally right or wrong