keep a civil tongue in your head
US /kiːp ə ˈsɪv.əl tʌŋ ɪn jʊər hɛd/
UK /kiːp ə ˈsɪv.əl tʌŋ ɪn jʊər hɛd/
1.
to speak politely and avoid rude or offensive language
:
•
You need to keep a civil tongue in your head when talking to your elders.
•
Even when angry, try to keep a civil tongue in your head.