プログレッシブ和英中辞典(第4版)の解説
さがしあてる【捜し当てる・探し当てる】
⇒さがしだす（捜し出す・探し出す）find (out)；〔所在・位置をつきとめる〕locate
警察は彼の居所をついに捜し当てた
The police finally 「found out where he was [tracked him down/located him].
大辞典でその語をやっと捜し当てた
I looked in an unabridged dictionary and finally found the word.