Definition of episteme:
(n) :
(philosophy) Scientific knowledge; a principled system of understanding; sometimes contrasted with empiricism.
(n) :
(specifically Foucaultian philosophy) The fundamental body of ideas and collective presuppositions that defines the nature and sets the bounds of what is accepted as true knowledge in a given epistemic epoch.
(n) :
(specifically Ancient Greek philosophy) Know-how; compare techne.