The Collaborative International Dictionary of English v.0.48:

Heading \Head"ing\, n.
   1. The act or state of one who, or that which, heads;
      formation of a head.
      [1913 Webster]

   2. That which stands at the head; title; as, the heading of a
      paper.
      [1913 Webster]

   3. Material for the heads of casks, barrels, etc.
      [1913 Webster]

   4. (Mining, tunneling)
      (a) A gallery, drift, or adit in a mine; the vein above a
          drift.
      (b) The end of a drift or gallery; also, the working face
          at the end of a tunnel, gallery, drift, or adit from
          which the work is advanced.
          [1913 Webster +RDH]

   5. (Sewing) The extension of a line ruffling above the line
      of stitch.
      [1913 Webster]

   6. (Masonry) That end of a stone or brick which is presented
      outward. --Knight.
      [1913 Webster]

   Heading course (Arch.), a course consisting only of
      headers. See Header, n. 3
      (a) .

   Heading joint.
      (a) (Carp.) A joint, as of two or more boards, etc., at
          right angles to the grain of the wood.
      (b) (Masonry) A joint between two roussoirs in the same
          course.
          [1913 Webster]