frown on - Phrases/Idioms
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Regard with disapproval or distaste, as in Pat frowns on bad language. this idiom transfers the disapproving facial expression to the thought it expresses. [Late 1500s]