Unctuous

doucereux

(of a person: profusely polite, especially in an insincerely earnest and unpleasant manner)

mielleux

(of a person: profusely polite, especially in an insincerely earnest and unpleasant manner)

onctueux

(of a liquid, etc.: having the nature or properties of an unguent or ointment — see also oily, greasy)

patelin

(of a person: profusely polite, especially in an insincerely earnest and unpleasant manner)