Choice Of Words
Word Use, Wording
noun, verbal noun
You may remember 言葉 means "word" and 遣う means "to use." That makes this your choice of words or, more simply, your word use.
The reading is 言葉 and 遣う combined together.
あの人は言葉遣いがとてもていねいです。
That person is very polite in their choice of words.
若手時代は、先輩からよく言葉遣いを注意されました。
When I was younger, my seniors often warned me about my language.
誰かの言葉遣いを真似することは、外国語の良い勉強法です。
Imitating someone's manner of speech can be a good way to practice a foreign language.