There is actually a significant discrepancy in definitions of this term within the CFD community. I follow the AIAA (and common sense) definition:
“The process of adjusting numerical or physical modeling parameters in the computational model for the purpose of improving agreement with experimental data.”
ERCOFTAC uses a definition for “calibration” that captures an aspect of Validation:
“Procedure to assess the ability of a CFD code to predict global quantities of interest for specific geometries of engineering design interest.”
They specifically reject use of the AIAA definition.