1. a person who uses a knife, especially in combat or as a weapon
Usage: informal; often used in military or combat contexts
2. a person who stabs or attacks with a knife
Usage: informal; can carry negative connotations

Examples

• The soldier trained as a knifer in close-quarters combat.
• Police arrested the knifer who had attacked several people in the neighborhood.
• In the old days, a skilled knifer was valued in hand-to-hand fighting.
• The character in the film was portrayed as a dangerous knifer.
• Military instructors taught recruits to be effective knifers when firearms were unavailable.