cut-throat n
1 assassin, bravo, butcher, executioner, heavy (slang) hit man (slang) homicide, killer, liquidator, murderer, slayer (archaic) thug adj
2 barbarous, bloodthirsty, bloody, cruel, death-dealing, ferocious, homicidal, murderous, savage, thuggish, violent
3 competitive, dog-eat-dog, fierce, relentless, ruthless, unprincipled