亀の甲より年の劫
(Kame no kou yori toshi no kou;
“Better the wisdom of years than a tortoise-shell”)

Definition:

Pun time! Japanese is actually full of puns, and here’s one that made it into a kotowaza. The phrase itself means that one should honor and value the knowledge and wisdom that comes from the experience of many years of life. Despite the phonetic play at work here, the meaning is also serious: apparently in the old days turtle-shell was valued for its uses both in jewelry and in divination. This saying asserts experience is both more valuable – and more accurate in determining what course of action to take – than the shell.

Breakdown:

We begin with noun 亀 (kame), “turtle” or “tortoise,” with the associative particle の (no), um, associating it with noun 甲 (kou), “shell.” This whole noun phrase is marked by the particle より (yori) as less (useful/valuable) than the noun 劫 (kou), “long ages,” “many years.” This in turn is associated by particle の with the noun 年 (toshi), “year(s).”

Notes:

劫 is the original version, but it may be replaced with homophone 功, “merit,” without any change in the meaning of the phrase as a whole. That said, using 効 (also kou; “effect,” “result”) is considered an error. And apparently some people interpret the toshi no kou part as simply meaning “to get older,” which is of course a misunderstanding.

Example sentence:

「占いなんて要らないさ、私の祖母ちゃんに尋ねてみよう。亀の甲より年の劫よ」　「こっくりさんは本気の占いじゃないよ、遊びだよ、遊び」

(“Uranai nante iranai sa, watashi no baachan ni tazunete miyou. Kame no kou yori toshi no kou yo.” “Kokkuri-san wa honki no uranai ja nai yo, asobi da yo, asobi.”)

[“We don’t need any fortune-telling, let’s just try asking my grandma. There’s a lot of value in experience, you know.” “Kokkuri-san isn’t real fortune-telling; it’s a game. A game.”]