Is a propeller a wing? An aviation expert claimed to me that a propeller is a wing.

While I understand that propellers use similar principles to generate force, it muddied the definition of a rotary wing aircraft vs a fixed wing aircraft.  If the propeller of a fixed wing aircraft is considered a wing, what is the distinction between the two?  Is it how much surface area each type of wing works on?  Is it the direction of force?
I think most people would say the answer is no. Consider the dictionary.com definition as it relates to Aeronautics:


  9. Aeronautics .
  a. one of a pair of airfoils attached transversely to the fuselage of an aircraft and providing lift.
  b. both airfoils, taken collectively.


The wings are the big airfoils which are responsible for generating most of the vertical lift.

A colloquial test of this definition would be to grab a CFI and ask him/her to "point out the wings on this airplane to me." They won't point out the propeller. (Not a scientific experiment)

However, both wings and propellers are airfoils (and so are the other wing-like surfaces such as the vertical and horizontal stabilizers). You might get some disagreement about whether those other surfaces are wings, but I believe the answer is still no. There is nothing to be gained by calling them wings, and only leads to ambiguity. We already have a word which describes lifting surfaces in-general, and again, it's airfoil.