Many times; repeatedly — an adverb indicating something occurs over and over.
何回も説明したのに、まだわからないと言う。
Even though I explained it many times, they still say they don't understand.
彼は何回も電話をかけてきた。
He called many times.
同じミスを何回も繰り返してはいけない。
You shouldn't make the same mistake over and over.