Structural Engineering is the science and art of designing and making, with economy and elegance, buildings, bridges, frameworks and other similar structures so that they can safely resist the forces to which they may be subjected.

More Probable Definition:

Structural Engineering is the art of molding materials we do not entirely understand into shapes we cannot precisely analyze so as to withstand forces we cannot really assess, in such a way that the community at large has no reason to suspect the extent of our ignorance.

....From SEAOC Newsletter