Answer:

knifer

Answer	Crossword Clue
KNIFER	Macbeth, vis- -vis Duncan
KNIFER	Jack the Ripper, e.g.
KNIFER	Certain attacker

KNIFER	Dangerous assailant
KNIFER	Assailant without a gun
KNIFER	Macbeth, to Duncan

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.