A discourse or treatise on an art or arts;
The scientific study of the practical or industrial arts.
Techne (art, craft, skill), Logos (word).
Some other attempts at definitions:
A system based on the application of knowledge, manifested in physical objects and organizational forms, for the attainment of specific goals —Volti
Cumulative sum of means used to satisfy human needs and desires and to solve specific problems —Markert