Unctuous
adj.

1. Characterized by affected, exaggerated, or insincere earnestness:
“the unctuous, complacent court composer who is consumed with envy and self-loathing”

2. Having the quality or characteristics of oil or ointment; slippery.

3. Containing or composed of oil or fat.

4. Abundant in organic materials; soft and rich: unctuous soil.


[Middle English, from Old French unctueus, from Medieval Latin nctusus, from Latin nctum, ointment, from neuter past participle of unguere, to anoint.]
unctu·ous·ly (adv)
unctu·ous·ness or unctu·osi·ty (n)

Synonyms: unctuous, fulsome, oily, oleaginous, smarmy

(These adjectives mean insincerely, self-servingly, or smugly agreeable or earnest: an unctuous toady; gave the dictator a fulsome introduction; oily praise; oleaginous hypocrisy; smarmy self-importance)