Dictionary:

oleaginous

  (ō'lē-ăj'ə-nəs)

1. Of or relating to oil.
2. Falsely or smugly earnest; unctuous: oleaginous flattery. See synonyms at unctuous.

[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.]

adjective

1. Having the qualities of fat: adipose, fat, fatty, greasy, oily, unctuous. See fat/thin.
2. Affectedly and self-servingly earnest: fulsome, oily, sleek, smarmy, unctuous. See attitude/good attitude/bad attitude/neutral attitude, honest/dishonest.

Oily; greasy.

adj.

Oily, smooth, sleek.

Disraeli once described the manner of Bishop Wilberforce as "unctuous, oleaginous, saponaceous." And the good prelate was ever afterward known as Soapy Sam. For every man there is something in the vocabulary that would stick to him like a second skin. His enemies have only to find it.