Definitions of frontal:

• noun:   a drapery that covers the front of an altar
• noun:   an adornment worn on the forehead
• noun:   the face or front of a building
• adjective:   of or relating to the front of an advancing mass of air

  Example: "Frontal rainfall"

• adjective:   belonging to the front part

  Example: "A frontal appendage"

• adjective:   of or adjacent to the forehead or frontal bone

  Example: "The frontal lobes"

• adjective:   meeting front to front

  Example: "A frontal attack"