You searched for: “mortar
mortar
1. Material for sticking things together; such as, a wet substance that is spread between bricks or stones and which holds them together when it hardens.
2. A device, or weapon, for blowing things apart with shells; "The soldiers came under mortar fire."

Bricks require mortar to stick, or hold, them together, but a mortar shell would blow apart a brick wall.

This entry is located in the following unit: Contranyms (page 1)