From Longman Dictionary of Contemporary Englishthat is to saythat is to sayEXPLAINused before giving more details or being more exact about something They, that’s to say Matt and John, were arguing about what to do. → say
Examples from the Corpus
that is to say• She has always known as much, that is to say as little, as the supplier needed her to know.that is (to say)that is (to say)MEANINGused to give more exact information about something or to correct a statement One solution would be to change the shape of the screen, that is, to make it wider. Languages are taught by the direct method, that is to say, without using the student’s own language. I loved him – that is, I thought I did. → thatExamples from the Corpus
that is (to say)• Could you describe the current selling collection hanging out there in a gallery that is also your front room?• But it is not a dream that is likely to come true, though perhaps not for the obvious reason.• You won't convince me that the answer to that is necessary for your enquiry.• I look to the current discussions, and also to the United States, to give the ground that is needed.• First, that is not so.• Scientific knowledge is not proven knowledge, but it does represent knowledge that is probably true.• A standard of service that is second to none, with a speed and quality guarantee for all repairs.• One solution would be to change the shape of the TV screen -- that is, to make it wider.• Uncomplicated computer interface that is truly easy to use. 