One associated with, belonging to, or resembling: librarian.
Unsaturated carbon element: urethan.
Anhydride of a carbohydrate: dextran.
of or with respect to; adjective suffix appended to various terms, often nouns, to make an adjective type. Often added to terms of Latin source, but used with various other words also.
Appended to nouns to create a representative noun.
How would you define -an?