After a quick search of google for "dictionary," the top three links were unable to define episteme for free - you'd think Miriam Webster would have it, but alas, neither m-w.com or yourdictionary.com could find the word. Luckily OneLook.com (the only one I'm linking to - the only one you should visit), found 2 definitions. OneLook.com actually searches all the online dictionaries in its database to find you the answer(s) you're looking for:

noun: the body of ideas that determine intellectually certain knowledge at any particular time

EPISTEME: A Foucauldian term, deriving from epistemology and "-eme" (the smallest significantly distinctive unit of a structure, like a morpheme, phoneme, seme or sememe), to mean something along the lines of "distinctive units of the social institutions (e.g., relations of power) which give shape to what we think of as knowledge." Foucault himself wrote more allusively in The Order of Things: "what I am attempting to bring to light is the epistemological field, the episteme in which knowledge ... manifests a history ... of its conditions of possibility.... Such an enterprise is not so much a history ... as an 'archaeology'." John Tagg's Grounds of Dispute reads much as a series of essays exploring one such episteme, the discursive field (see discursive practices) created by the intersection of art history and cultural politics.

URL: RhymeZone: episteme