There is a glossary in the back of the Blue Book of Modern Blackpowder Arms. I'd say that most pricing guides have a glossary of some kind.
Fluted Cylinder - A cylinder with concave indentations or grooves between the chambers. The fluted and semi fluted (read half fluted, ed.) cylinder is still the basic design for revolver cylinders manufactured in the world today.
A modern Colt SAA has a half fluted cylinder.