3 Terms and definitions [intro.defs]

3.18[defns.dynamic.type]dynamic type

⟨glvalue⟩ type of the most derived object to which the glvalue refers
[Example 1: 
If a pointer p whose static type is “pointer to class B” is pointing to an object of class D, derived from B, the dynamic type of the expression *p is “D.
References are treated similarly.
— end example]