The branch of philosophy that examines the nature of knowledge, its presuppositions and foundations, and its extent and validity.
[Greek epistēmē, knowledge (from epistasthai, epistē-, to understand : epi-, epi- + histasthai, middle voice of histanai, to place, determine; see stā- in the Appendix of Indo-European roots) + -LOGY.]
e·pis′te·mo·logi·cal (-mə-lŏjĭ-kəl) adj.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.