1. the quality of being excessively smooth, suave, or insincerely earnest in manner or speech
Usage: often implies insincerity or false piety
2. the quality of being greasy or oily in texture
Usage: literal sense referring to physical texture

Examples

• The politician’s unctuousness made voters question his sincerity.
• She was put off by the salesman’s unctuousness and obvious flattery.
• His unctuousness during the apology suggested he didn’t really mean it.
• The unctuousness of the lotion made it difficult to apply evenly.
• The preacher’s unctuousness seemed more theatrical than genuine.
• The unctuousness of the ointment helped soothe the irritated skin.