transitive verb
1. : to shut from view : screen
that vine on the porch blocks out all the sunlight
a. : to prevent (a part of a photographic negative) from printing by painting over with opaque or a comparable substance
b. : to cancel (printed matter) by overprinting with a solid patch of ink
2.
a. : to excavate (as ore and gravel) by making a drive in the wall and taking out the material in blocks or strips along the sides of the drive
b. : to subdivide (a lode) into blocks in advance of the working stopes by shafts, winzes, and intersecting drives or levels so as to be ready for stoping and to keep a known amount of reserve ore in sight