1. Of or relating to oil.
2. Falsely or smugly earnest; unctuous: oleaginous flattery.
[From Middle English oliaginose and from French oléagineux (from Old French), both from Latin oleāginus, of the olive tree, from olea, olive tree, alteration (influenced by oleum, olive oil) of olīva; see OLIVE.]
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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.