mor ‧ al ‧ ist ‧ ic /ˌmɒrəˈlɪstɪk◂ $ ˌmɔː-/ BrE AmE adjective
[ Word Family: noun : ↑ moral , morals, ↑ morality ≠ ↑ immorality , ↑ moralist , ↑ amorality ; adjective : ↑ moral ≠ ↑ immoral , ↑ amoral , ↑ moralistic ; verb : ↑ moralize ; adverb : ↑ morally ≠ ↑ immorally ]
with very strong beliefs about what is right and wrong, especially when this makes you judge other people’s behaviour:
It’s difficult to talk to teenagers about drugs without sounding too moralistic.