Basically, it's a continuous concrete slab or beam. In the same family as Image 1 - http://www.emeraldinsight.com/content_im...
Concrete that has all been poured in one piece.
A foundation, for example, is usually done in two pours: the footing first, and after it sets the walls are formed and poured.
A monolithic pour is a method of forming the walls and footing at the same time, and then pouring them at the same time.
