This is the 9824th most frequent Japanese word.
見つから
"見つから" means "to be found" or "to be discovered" (plain negative stem form of the verb 見つかる).
In this sentence, '見つからない' is in its negative form, indicating that the wallet has not been located or found.
財布が見つからない。
I can't find my wallet.
Here, '見つかった' is used in past tense, showing that the child has been located.
子供が見つかった時、彼らは安心した。
When the child was found, they felt relieved.
The phrase '見つかった' conveys the successful discovery of a new interest or hobby by the subject.