This a new word that I learned from Miss Leong. (English Studies lecturer)
I checked Macmillan dictionary, which means intended to teach something (moral lesson), but often in a annoying way.
Sometimes, its good to be didactic, just like Aunt Alexandra in To Kill A Mocking Bird. Simply because she is responsible for Atticus' family. Scout dislikes her because the way she talks and express her feeling are annoying. Aunt Alexandra would arrange, advise, caution and warn Jem and Scout all the times.
Aunt Alexandra reminds me of my mum. She is didactic too. The main reason is my dad is away from home. She is the only one in my family, who gives advise, plan, and take care of us, especially me. She is a very ordinary woman or housewife. In my eyes, she is superwoman. She concerns of our daily meals, especially breakfast, eduction as well as my financial problems. She is an incurable gossip too. She never bored. She runs for whole the family members when my dad is away.
Thank you mum of ur didactic.