noun
unction
UNK-shun/ˈʌŋkʃn/
Exaggerated or soothing earnestness in speech or manner.
The salesman speaks with such unction that his promises sound rehearsed.

Etymology
The literal image is anointing or smearing with ointment. The figurative sense applies that oily smoothness to speech or manner, especially when earnestness feels excessive or insincere.
More examples
- She delivers her apology with more unction than genuine regret.
- His voice drips with unction as he asks for another favor.
- She speaks with soothing unction to calm the anxious crowd.
Forms
unction
unctuous adjective — Excessively earnest or insincerely flattering in manner.
Similar words
- smarminess
- Emphasizes insincere flattery intended to win someone's approval.
- earnestness
- Can be entirely sincere, without exaggerated or soothing delivery.