Answer: cutthroat

AnswerCrossword Clue
CUTTHROATRuthless
CUTTHROATDOG-eat-DOG
CUTTHROATMurderous person
CUTTHROAT...competition
CUTTHROATDog-eat-dog
cutthroata murderer, an assassin
cutthroatA murderer or other violent criminal
cutthroatA trout of western North America, with red or orange markings under the jaw