sermonize

US /ˈsɝː.mə.naɪz/
UK /ˈsɝː.mə.naɪz/
"sermonize" picture
1.

deliver a sermon or moral lecture to someone, especially tediously or dogmatically

:
He tends to sermonize about the importance of hard work.
Please don't sermonize me; I already know what I should do.