Chinese character 诣

It means reaching, going to, or attaining a high level.

The character behind 诣 and its traditional form 詣 is attested in manuscript traditions from the Warring States period and in the Han era's Shuowen Jiezi, an early Chinese dictionary. That dictionary analyzes 诣 as built from 言, the meaning-bearing part, and 旨, the sound-bearing part.

In classical Chinese, 诣 is a literary verb for going to a person of higher rank and reporting there. Its destination sense also carries into 造诣, where the destination becomes a level of learning or craft.

How does 诣 change across Chinese and Japanese?

The language and compound change its reading and sense.

In modern Chinese, dictionaries retain senses of going somewhere or visiting a superior, while 造诣 names expertise. 苦心孤诣 describes a level reached through painstaking effort. The Japanese form 詣 appears in compounds such as 造詣 and 参詣; the verbs いたる (reach) and もうでる (visit a shrine or temple) preserve distinct senses.

Why does an old dictionary connect 诣 with 致?

It links them through the idea of reaching a destination.

The Shuowen Jiezi entry for 致 uses 送詣, a phrase meaning to send someone or something to its destination. This is a semantic connection between the characters, not evidence that 致 and 诣 can replace one another.