1. mortar (a relatively lightweight, often portable indirect fire weapon which transmits recoil to a base plate and is designed to lob explosive shells at very steep trajectories) (military)

2. mortar, mortar and pestle, pestle and mortar (a hollow vessel used to pound, crush, rub, grind or mix ingredients with a pestle) (food)

3. mortar (a mixture of lime or cement, sand and water used for bonding building blocks)

4. a huge firecracker (Honduras, El Salvador, Nicaragua)