If an agreement, policy, or rule is set in stone, it is completely decided and cannot be changed. The exact terms of the scheme have yet to be set in stone. ... Note: Other verbs such as carved or cast can be used instead of set.

What does to set in stone mean?

said to mean that something such as an agreement, policy or rule is not permanent and that it can be changed.

Where did the expression set in stone come from?

Granite: Origin of “Set in Stone” This phrase first came to widespread popularity in the 18th century, when people started to make tombstones out of stone and granite.