adj. 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.] o′le·agi·nous·ly adv. |
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