In everyday spoken language, what's more stronger in meaning of "not interesting", is it "dull" or "boring"?
According to Oxford dictionary:
dull: Lacking interest or excitement.
boring: Not interesting; tedious.
N.b. can I say about a show, person, lecture, even, teacher etc, that they are dull?
Based on that, they seem to be the same or synonyms (I don't really remember when I heard dull in such context. What I used to hear is the dull as a synonym of sharp.)