Unctuously

adv. [f. prec. + -LY².] In an unctuous manner; with unction.

1864.  Webster.

1872.  Goldw. Smith, in Fortn. Rev., March, 246. The [religious] faith in the name of which the aristocracy had unctuously stolen the property of the nation.

1888.  Miss Braddon, Fatal Three, I. v. ‘I think hers is about the best case,’ answered the Doctor unctuously.