civil tongue

idiomatic

(idiomatic) A polite manner of speaking.

Japanese Meaning

丁寧で礼儀正しい話し方 / 上品な言葉遣い / 礼儀正しい物言い

He taught his students to adopt a civil tongue when debating sensitive topics.

彼は、デリケートな問題を議論するときには礼儀正しい話し方を身につけるよう生徒たちに教えた。

Sense（1）

(idiomatic) A polite manner of speaking.

[T]here would not have been the least offence had the youth only possessed a civil tongue.

civil tongues

（ plural ）