that is to say
idiomPart ofsay
that is to say — idiom
1. used to introduce a clearer or more detailed explanation of what you have just s
1.idiom
Definition
used to introduce a clearer or more detailed explanation of what you have just said.
Example
We need to leave on Friday — that is to say, two days from now.
The project was a failure; that is to say, it did not meet any of its goals.