This term is relatively new,
But without further ado:
Upon being asked to concisely define,
I'm sorry, I have to decline.
Especially - and this is the main research focus of this group - when considering NP-hard optimization problems, it often turns out that by using suitable techniques, computing provable optimal solutions may not be as practically intractable as expected…
For a more in-depth introduction into this growing research field, see, e.g.:
[M. Chimani and K. Klein. Algorithm Engineering: Concepts and Practice. Chapter in: Experimental Methods for the Analysis of Optimization Algorithms. T. Bartz-Beielstein, M. Chiarandini, L. Paquete, M. Preuss (Eds.), Springer 2010. (preprint)]