The term professional killer has a negative connotation as it refers to someone who is hired to murder another person for money or personal gain. However, there are several antonyms for this phrase that denote a positive or at least neutral meaning. Some of the antonyms include philanthropist, altruist, humanitarian, donor, helper, benefactor, volunteer, and savior. These words all refer to selfless acts that benefit others instead of harming them. They highlight the importance of empathy and kindness towards others, qualities that are necessary for building strong communities and societies. It is important to remember that every individual has the power to make a positive difference in the world.