Mortar has two meanings:-
A mortar is a crew fired weapon that consists of a short tube with support legs that form a tripod. There is an adjustment for the elevation (angle of the tube to the ground) and an adjustment for slight movement from side to side. For major changes in direction of fire the entire weapon is moved. A shell is dropped into the top opening of the tube and it fires when it hits the base. The shell travels in a high arc and descends at a steep angle to strike its target. This means that walls, trees, and parked vehicles do not obstruct the target. The shell generally explodes on impact although there have been tests with timed shells that explode in the air. Shells can be shrapnel or incendiary devices.[1]
Mortar is a paste made from cement, sand and lime. It is used in bricklaying as an adhesive to join bricks or blocks together. The lime makes the mortar softer than concrete.[2]