From the greek name Φιλιππος (philippos) which means "friend of horses". Though modern english translation now means 'lover of horses'. When combined with Atkin (Meaning consumer of meat from the penis of an animal), it means lover of horses penises, and after the 'lovin sesh' the horses penis will be consumed by the person.
Person 1: What the hell is that person doing to that horses penis?
Person 2: Oh don't worry, thats just Philip Atkin