Mortar is a workable paste used to bind building blocks such as
stones,
bricks, and
concrete masonry units together, fill and seal the irregular gaps between them, and sometimes add decorative colors or patterns in
masonry walls. In its broadest sense mortar includes
pitch,
asphalt, and soft mud or clay, such as used between
mud bricks.
Mortar comes from Latin
mortarium meaning
crushed.