Meaning of “frown on/upon sth” - Learner’s Dictionary

frown on/upon sth

phrasal verb with frown us uk /fraʊn/ verb [ I ]

to think that something is wrong and that you should not do it:

[ often passive ] Smoking is frowned upon in many public places.

(Definition of “frown on/upon sth” from the Cambridge Learner’s Dictionary © Cambridge University Press)