frowned upon

Verb

frown upon (third-person singular simple present frowns upon, present participle frowning upon, simple past and past participle frowned upon)

1. (transitive) To disapprove of.
   • Regular passengers become familiar with their train and attempts to change its make-up or any other aspect of its working are more often than not frowned upon, even though the change is probably for the better.1962 September, Warren Smith, “The problems of coaching stock rostering and operation”, in Modern Railways, page 193

   Synonyms:

   frown at, frown on