Episteme
"Episteme" is a philosophical term derived from the Ancient Greek word ἐπιστήμη "epistēmē", which can refer to knowledge, science or understanding, and which comes from the verb , meaning "to know, to understand, or to be acquainted with".
Epistemology
French philosophers then gave the term "épistémologie" a narrower meaning as philosophy of science. E.g., Émile Meyerson opened his "Identity and Reality", written in 1908, with the remark that the word 'is becoming current' as equivalent to 'the philosophy of the sciences.'