sociopath
//ˈsoʊ.si.oʊˌpæθ//
Noun
sociopathSingular
sociopathsPlural
1
A person with a personality disorder characterized by persistent antisocial behavior, impaired empathy and remorse, and bold, disinhibited, and egotistical traits.
The detective suspected that the criminal was a sociopath who felt no remorse for his actions.
2
(informal) A person who behaves in a manipulative, callous, or deceitful manner without regard for others' feelings.
He's such a sociopath—he manipulates everyone around him without any guilt.