Philip mentions the "dado" of an interior wall. This word can have many meanings. I first learned it for a device to make cirular saw tilt on its axle, so that it made a wide
cut.
DADO

In architecture, a dado is that part of a pedestal included between the base and the cornice (or surbase), and in a wall, that part of the basement included between the base and the base course. In interior decoration, the dado is the lower part of the wall of an apartment when adorned with mouldings, or otherwise specially decorated.

Oh, fuss and nonsense! It is so very difficult to visualize some of these terms when I haven't seen an illustration!

And googling images is a dangerous game since there are so many random images there at times that don't have squat to do with what you're looking for! Now where in Sam's Hill would these mouldings be? Are we talking about crown moldings or moldings for wainscot--or what?

DADO is an acronym. It stands for DADO And DADO Only.

I'd heard that a dado was a groove made in two different pieces of wood so they could be abutted and connected. There's a lozenge thingee (biscuits) that goes into the two grooves and holds the boards together. The guy on the New Yankee Workshop on PBS is always going on about them in connection to furniture making.

http://www.newyankee.com