set in concrete
idiomPart ofconcrete
set in concrete — idiom
1. completely fixed and impossible to change — used about rules, plans, or decision
1.idiom
Definition
completely fixed and impossible to change — used about rules, plans, or decisions that are no longer open to discussion.
Example
The company's budget is not set in concrete yet, so we can still ask for more money.
Marta thought the holiday dates were set in concrete, but her boss agreed to change them.