しらみつぶしに

adverb

one by one; thoroughly; exhaustively

Describes doing something meticulously, covering every single item or possibility without skipping any. Often used with verbs like 調べる, 探す, or 当たる.

• 警けい察さつはその地ち域いきをしらみつぶしに捜そう索さくした。

  The police searched the area exhaustively, going door to door.

• 間ま違ちがいがないか、書しょ類るいをしらみつぶしにチェックした。

  I checked the documents with a fine-tooth comb for any mistakes.