expression, godan verb (-mu)
watch one's words; mind one's language
Used when someone is careful about what they say, often to avoid offending others or causing trouble. Similar to 口を慎む.
See also: 口を慎む
上司の前では言葉を慎んだほうがいい。
You should watch your language in front of the boss.
彼
He held back his anger and chose his words carefully.