[defns.dynamic.type]

3 Terms and definitions [intro.defs]

3.19[defns.dynamic.type]dynamic type

⟨glvalue⟩ type of the most derived object to which the glvalue refers

[Example 1: 

If a pointer p whose type is “pointer to class B” is pointing to a base class subobject of class B, whose most derived object is of class D, derived from B, the dynamic type of the expression *p is “D.

References are treated similarly.

— end example]