mortar

[count] : a heavy, deep bowl in which seeds, spices, etc., are pounded or crushed with a heavy tool (called a pestle)

[count] : a military weapon used to fire shells (sense 5a) high into the air at a low speed — often used before another noun

[noncount] : a wet substance that is spread between bricks or stones and that holds them together when it hardens — see also brick-and-mortar, bricks and mortar at ¹brick