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to express; to show
「表す」 has another reading with different meanings.
彼は卒業式で感謝の気持ちを涙で表した。
He expressed his gratitude.
言葉では表せない感動だった。
It was emotion that cannot be expressed in words.
言葉だけでなく態度で誠意を表すべきだ。
You should express sincerity through actions.