言葉遣い
ことばづかい · kotobadukai · JLPT N2 · noun
address
言葉 (kotoba, word) + 遣い (tsukai, use/handling) = how you handle your words
言葉遣い is kotoba (words) plus tsukai (usage, handling), so it names the way you choose and handle your wording, like politeness level. Think of it as how you handle words.