Definitions of knifelike:

• adjective:   having a sharp or distinct edge

  Example: "A narrow knifelike profile"

• adjective:   cutting or able to cut as if with a knife
• adjective:   as physically painful as if caused by a sharp instrument

  Example: "Knifelike cold"

• adjective:   having or demonstrating ability to recognize or draw fine distinctions

  Example: "Icy knifelike reasoning"