Driven Dimension
    
PTC : PTC Fundamentals, MBD, and Assembly Glossaries
Dimensions in a drawing file derived from the 3D model. Driven dimensions reflect changes to part or assembly geometry, but you cannot modify their values in the drawing. The association is one-way; from the model to the drawing.
Alternate Definitions:

PTC - A dimension that is derived from the 3D model and cannot be directly modified.