Function that returns a value of local variable is also called getter?

You could ... but getters and setters are terms specifically used in pairs to allow encapsulation of your variables within a class.

Unlike C#, C++ doesn't support properties directly, so the name prefixes "get" and "set" are conventionally used to help the reader understand what is going on.

class Employee 
    {
    private:
       int salary;

    public:
        void setSalary(int s) { salary = s; }
        int getSalary() { return salary; }
    }
...
myEmployee.setSalary(56000);
int x = myEmployee.getSalary();

In C# it's a little more elegant, and you use the property as if it was a variable instead of calling functions directly:

class Employee 
    {
    private int salary;
    
    public int Salary 
        {
        get { return salary; }
        set {salary = value; }
        }
    };
...
myEmployee.Salary = 56000;
int x = myEmployee.Salary;

Or even:

class Employee 
    {
    public int Salary { get; set; }
    };
...
myEmployee.Salary = 56000;
int x = myEmployee.Salary;

And the backing variable will be handled automatically.