This is the 460th most frequent Polish word.
dobry
"Good."
'Dobry' is used here as an adjective describing the quality of the teacher.
Dobry nauczyciel zawsze pomaga swoim uczniom.
A good teacher always helps their students.
In this case, 'dobry' is part of a common greeting in Polish, standing for 'good' in 'good morning'.
Dzień dobry, jak się masz?
Good morning, how are you?
'Dobry' describes the quality of the movie, emphasizing its positive attributes.