秘ひ中ちゅうの秘ひひちゅうのひMeanings1expression, nountop secret; most confidentialEmphatic expression meaning the most secret of secrets; used for information that is extremely confidential.この書しょ類るいは秘ひ中ちゅうの秘ひだから、誰だれにも見みせてはいけない。This document is top secret, so you must not show it to anyone.
