Date: 11 Jul 2002

I'm not entirely happy with definitions, but here is one:
  *  *IEEE Standard Computer Dictionary*, 610, ISBN 1-55937-079-3, 1990:
     The application of a systematic, disciplined, quantifiable approach to
     development, operation, and maintenance of software; that is, the
     application of engineering to software.

Textbooks tend not to give definitions, but instead spend their introductory
chapters explaining characteristics of the discipline.  Interesting phrases
include:
  *  Ian Sommerville, *Software Engineering*, 5th edition, Addison-Wesley,
     1996.
     The specification, development, management, and evolution of software
     systems.  Not constrained by materials governed by physical laws or
     manufacturing processes.  Theories, methods, and tools needed to develop
     software.  Evolving models of the real world.
  *  Stephen R. Schach, *Software Engineering*, 2nd Edition, Richard D.Irwin,
     Inc. and Aksen Associates, 1993.
     A discipline whose aim is the production of quality software, delivered
     on time, within budget, and satisfying users' needs.
  *  Shari Lawrence Pfleeger, *Software Engineering: the Production of Quality
     Software*, 2nd Edition, Macmillan, 1991, ISBN 0-02-395115-X.
     Designing and developing high-quality software.  Application of computer
     science techniques to a variety of problems.  We are problem-solvers
     rather that theoreticians.