That decision defines the actor. Most human beings in civilized societies are required by law and expected by Society to take responsibility for their actions. That responsibility leads to legal and moral accountability for actions taken. The 'amoral' actor. The moral imbecile and the wild animal.
Some human beings are incapable of being legally or morally responsible for their actions.
They have psychopathic personalities. Human beings suffering from this disorder are said to make 'amoral' decisions. Wild animals who kill prey for food are regarded by men as incapable of knowing the difference between right and wrong. That condition is defined as 'amoral' also. Therefore we can see that 'amorality' is an appropriate term for moral imbeciles, non judgmental approaches to generally recognized debatable or conflicting moral views, and wild animals.