na-adjective, noun which may take the genitive case particle 'no', noun
failure; unsuccessful
Used for attempts, actions, or outcomes that end in failure. Often appears in formal or written contexts.
His plan ended in failure.
We need to analyze the cause of the failure.
unsuccessful execution
Compound of 不 (fu, 'not') + 成功 (seikō, 'success'). The kanji 不 is a common negative prefix, and 成功 is a Sino-Japanese word meaning success.