sermonising
ser-mon-is-ing
verb
Giving a long, often tedious, moral lecture to someone.
"He was sermonising about their poor choices."
noun
The act of giving a long, often tedious, moral lecture to someone.
"His constant sermonising became quite tiresome."
Thesaurus
Synonyms: preachify, sermonize, sermonise, moralize, moralise