丁砖层
露头砖层

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

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

3. Material for the heads of casks, barrels, etc.

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 +RH]

5. (Sewing) The extension of a line ruffling above the line
of stitch.

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

{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.