Dave, most sources define Fusil as a "light French musket". Any French smoothbore that is not a large caliber heavy musket could be considered a fusil. There are many types of fusils, as a fusil de chasse, (fusil for the chase or hunt, these are usually plain and un adorned). Fusil fin, (a fine fusil, but you could also have a "fusil fin de chasse" or a fine hunting fusil). a fusil St Etienne would be simply a "light musket made at St Etienne" but you could also have a "fusil fin de chase St. Etienne", that would be a fine hunting fusil made a St Etienne...WHEW!!!!! It is also used today to describe modern firearms as in fusil de chasse Beretta, ( a Baretta hunting shotgun), fusil de asalto, (an Assult rifle) etc...
Yes, your "light french musket" is definately a fusil, and the English counterpart is "fowler".....Ed