noun
Literary term for an ideal example or pattern to follow, often used in formal or written contexts. The kanji literally mean 'tortoise mirror', referring to an ancient practice of using a tortoise shell as a mirror for reflection.
彼の生き方はまさに亀鑑だ。
His way of life is truly a model to follow.
この書は経営者の亀鑑とされている。
This book is regarded as a mirror for managers.
From Chinese 龜鑑 (guījiàn), literally 'tortoise mirror', referring to the ancient use of tortoise shells for divination and as mirrors. The word entered Japanese as a literary term for a model or paragon.