Meaning of the word "set the seal on" in English

What does "set the seal on" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

set the seal on

US /sɛt ðə siːl ɒn/
UK /sɛt ðə siːl ɒn/

Idiom

to finalize or confirm something, often in a way that makes it certain or official

Example:
The signing of the contract will set the seal on our partnership.
His victory in the final match set the seal on a brilliant career.