adjective

1. 1. of, like, or characteristic of an ointment or unguent; oily or greasy
   2. made up of or containing fat or oil
2. like oil, soap, or grease to the touch: said of certain minerals
3. soft and rich: said of soil
4. plastic; moldable
5. characterized by a smug, smooth pretense of spiritual feeling, fervor, or earnestness, as in seeking to persuade; too suave or oily in speech or manner

Etymology: ME < ML unctuosus, greasy < L unctum, ointment < ungere, to anoint: see unguent