mortar

noun

1. (uncountable)A mixture of lime or cement, sand and water used for bonding building blocks.

   “The holy hearth! If any earthly and material thing, or rather a divine idea embodied in brick and mortar, might be supposed to possess the permanence of moral truth, it was this.”

2. (countable)A hollow vessel used to pound, crush, rub, grind or mix ingredients with a pestle.
3. (countable, historical)A short, heavy, large-bore cannon designed for indirect fire at very steep trajectories.
4. (countable)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.
5. (countable)In paper milling, a trough in which material is hammered.

verb

1. (transitive)To use mortar or plaster to join two things together.
2. (transitive)To pound in a mortar.
3. To fire a mortar (weapon).
4. To attack (someone or something) using a mortar (weapon).

   “The insurgents snuck up close and mortared the base last night.”