Compact cameras are those that are smaller than the alternatives. In the context of the SLRs of the time, the Konica Hexar was a compact camera, but it would not have fitted in most pockets. Indeed, in the context of today's DSLRs, the Fujifilm X100 too is a compact camera.
When talking about compacts today people don't think of old compact folders but of handy cameras with several automatic features: automatic film advance, automatic exposure, automatic focusing, automatic closing of the lens cover after usage, and automatic flash. Several very compact viewfinder cameras like the Olympus XA which don't have all of these features are still mentioned as compact cameras too.
Most digital cameras (SLRs aside) are compact by the standards of film cameras.
|the Olympus camera in the middle|
would normally be called compact
image by Tsutomu Otsuka (Image rights)
Older cameras which were designed and marketed as very compact models of their class may still impress through their compactness. Considering folding bed cameras one might think the design goal of cameras like the Conley Improved Compact Camera(1908) was finally achieved by KW in Dresden with the Patent Etui (1920), an extremely flat 9×12 format folder.