Framework region
A region in the variable domain of a protein which belongs to the immunoglobulin superfamily, and which is less "variable" than the CDR. As an example, each chain (alpha or beta) of the TCR is composed of 4 framework regions, separated by 3 CDR.
The nomenclature "framework" region comes from the fact that they would roll back at the moment of recognition of the antigen, making the 3 CDR closer to each other.