In Canada, a reasonable definition of "Experimental" s associated with the application for flight authority:
(2) Flight Permit - Experimental An experimental flight permit is issued for any aircraft, excluding aircraft that are operated under a special certificate of airworthiness in the owner-maintenance or amateur-built classification, which is manufactured for, or engaged in, aeronautical research and development, or for showing compliance with airworthiness standards.
It seems that Canada differs with the U.S., as an amateur built is very certainly not automatically "Experimental" in Canada.To get an experimental flight permit, I must provide a flight test plan, which, is essence, describes the experiment.