noun

• (figurative) A person with no moral conscience.
  "Now the real difference between now and then was that Trump wasn't looking to do much of anything positive for the American people as a whole. He mainly enriched himself and his family and gave rich people another tax cut. I think as far as Republicans being psychopaths I would say yes but it's probably a bit more complicated. The party is struggling to message against the policies the Biden administration is working to pass because they are overall popular with the voters. The Republicans would normally talk about fiscal responsibility and harp on the national debt but I think their big business "donors" don't want to see the economy stall again so we aren't seeing their normal talking points. So instead they are stoking their base with culture war crap about freedom and Biden becoming an authoritarian."
• (figurative) A person who perpetrates especially gruesome or bizarre violent acts.
• (obsolete) A person diagnosed with any mental disorder.