An adverb used to emphasize that something is truly or really the case; expresses strong affirmation or admiration.
彼の演奏は実に見事だった。
His performance was truly magnificent.
実に困った問題だが、根気よく取り組むしかない。
It's truly a troublesome problem, but we have no choice but to tackle it patiently.
実に、彼女の説明は分かりやすかった。
Indeed, her explanation was easy to understand.