slab

1 :  a thick plate or slice (as of stone, wood, or bread): such asa :  the outside piece cut from a log in squaring itb :  concrete pavement (as of a road); specifically :  a strip of concrete pavement laid as a single unjointed piecec (1) :  a flat rectangular architectural element that is usually formed of a single piece or mass a concrete foundation slab (2) :  a rectangular building having little width with respect to its length and usually height

2 :  something that resembles a slab (as in size, shape, or density) backed up by a solid slab of reference material — The Times Literary Supplement (London)

3 :  a hard plastic holder for a collectible coin and an identifying insert