What is Slab?

Slab definition and meaning on Dictionary terms:
a broad, flat, somewhat thick piece of stone, wood, or other solid material.
a thick slice of anything: a slab of bread.
a semifinished piece of iron or steel so rolled that its breadth is at least twice its thickness.
a rough outside piece cut from a log, as when sawing one into boards.

Baseball Slang. rubber1(def 14).
Building Trades. a section of concrete pavement or a concrete floor placed directly on the ground or on a base of gravel.

verb (used with object), slabbed, slab