Definition from Wiktionary, the free dictionary
- Oily, greasy.
- (of manner or speech) Falsely or affectedly earnest; persuasively suave.
- The oleaginous salesman convinced me to buy a more expensive car.
- (oily, greasy): greasy, oily, sebaceous, unctuous
- (falsely or affectedly earnest): fulsome, smarmy, unctuous