What is "blind blocking"

Blind \Blind\, a. [AS.; akin to D., G., OS., Sw., & Dan. blind, Icel. blindr, Goth. blinds; of uncertain origin.]

1. Destitute of the sense of seeing, either by natural defect or by deprivation; without sight.

   He that is strucken blind can not forget The precious treasure of his eyesight lost.
   --Shak.

2. Not having the faculty of discernment; destitute of intellectual light; unable or unwilling to understand or judge; as, authors are blind to their own defects.

   But hard be hardened, blind be blinded more, That they may stumble on, and deeper fall.
   --Milton.

3. Undiscerning; undiscriminating; inconsiderate.

   This plan is recommended neither to blind approbation nor to blind reprobation.
   --Jay.

4. Having such a state or condition as a thing would have to a person who is blind; not well marked or easily discernible; hidden; unseen; concealed; as, a blind path; a blind ditch.

5. Involved; intricate; not easily followed or traced.

   The blind mazes of this tangled wood.
   --Milton.

6. Having no openings for light or passage; as, a blind wall; open only at one end; as, a blind alley; a blind gut.

7. Unintelligible, or not easily intelligible; as, a blind passage in a book; illegible; as, blind writing.

8. (Hort.) Abortive; failing to produce flowers or fruit; as, blind buds; blind flowers.

   Blind alley, an alley closed at one end; a cul-de-sac.

   Blind axle, an axle which turns but does not communicate motion.
   --Knight.

   Blind beetle, one of the insects apt to fly against people, esp. at night.

   Blind cat (Zo["o]l.), a species of catfish ( Gronias nigrolabris), nearly destitute of eyes, living in caverns in Pennsylvania.

   Blind coal, coal that burns without flame; anthracite coal.
   --Simmonds.

   Blind door, Blind window, an imitation of a door or window, without an opening for passage or light. See Blank door or Blank window, under Blank, a.

   Blind level (Mining), a level or drainage gallery which has a vertical shaft at each end, and acts as an inverted siphon.
   --Knight.

   Blind nettle (Bot.), dead nettle. See Dead nettle, under Dead.

   Blind shell (Gunnery), a shell containing no charge, or one that does not explode.

   Blind side, the side which is most easily assailed; a weak or unguarded side; the side on which one is least able or disposed to see danger.
   --Swift.

   Blind snake (Zo["o]l.), a small, harmless, burrowing snake, of the family Typhlopid[ae], with rudimentary eyes.

   Blind spot (Anat.), the point in the retina of the eye where the optic nerve enters, and which is insensible to light.

   Blind tooling, in bookbinding and leather work, the indented impression of heated tools, without gilding; -- called also blank tooling, and blind blocking.

   Blind wall, a wall without an opening; a blank wall.