The Collaborative International Dictionary of English v.0.48:

Frontal \Fron"tal\, n. [F. frontal, fronteau, OF. Frontel,
   frontal, L. frontale an ornament for the forehead, frontlet.
   See Front.]
   1. Something worn on the forehead or face; a frontlet; as:
      (a) An ornamental band for the hair.
      (b) (Mil.) The metal face guard of a soldier.
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   2. (Arch.) A little pediment over a door or window.
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   3. (Eccl.) A movable, decorative member in metal, carved
      wood, or, commonly, in rich stuff or in embroidery,
      covering the front of the altar. Frontals are usually
      changed according to the different ceremonies.
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   4. (Med.) A medicament or application for the forehead.
      [Obs.] --Quincy.
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   5. (Anat.) The frontal bone, or one of the two frontal bones,
      of the cranium.
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   Frontal hammer or Frontal helve, a forge hammer lifted by
      a cam, acting upon a "tongue" immediately in front of the
      hammer head. --Raymond. Frontate