Period vs. Period-Style

As a general term, something which is period is something directly attested by primary sources, e.g. a recipe from a period source or an article of clothing which has been preserved; something which is period-style is something which attempts to be true to the style in primary sources, e.g. a recipe which, while not found in any period source, uses the same principles of healthy eating, available & likely food-stuffs and so forth, or an article of clothing which is cut similarly to an actual artifact.

Periodoid indicates something which is pseudo-period, e.g. honey-butter or a cloak with a vampire's picture on it. Periodoid things are not mediaeval and never were, but to our eyes (or some of our eyes) they appear to be.