Epistemology
The word "epistemology" is derived from the ancient Greek "epistēmē" meaning "knowledge" and the suffix "-logy", meaning "logical discourse" (derived from the Greek word "logos" meaning "discourse"). It is analogue to the German "Wissenschaftslehre" (literally, theory of science) which was introduced by philosophers Johann Fichte and Bernard Bolzano in the late 18th century. The word first appeared in English in 1847 as a translation of the German in New York's "Eclectic Magazine" review of a philosophical novel by German author Jean Paul:
Epistemic community
An epistemic community is a network of knowledge-based experts who help decision-makers to define the problems they face, identify various policy solutions and assess the policy outcomes. The definitive conceptual framework of an epistemic community is widely accepted as that of Peter M. Haas. He describes them as 
"...a network of professionals with recognised expertise and competence in a particular domain and an authoritative claim to policy relevant knowledge within that domain or issue-area."