1Failure or mistake: an unsuccessful result, error, or blunder where something did not go as planned.
実験は予想どおりには行かず、失敗に終わった。
The experiment did not go as expected and ended in failure.
何度も失敗を経験して、ようやく成功した。
After many failures, I finally succeeded.
小さな失敗を恐れてはいけない。
You shouldn't be afraid of small failures.