What is "concrete play"?

Concrete is a chess term that has arisen in the last 10 years along with the strength of computer play. When computers were applied to many opening positions, new moves that violated opening principles were found. These counter principle moves backed by tactical analysis needed a new term. Concrete moves are counter to general principle, but still good moves that are backed with analysis.

I think the term is becoming overused and possibly overloaded with new meanings.