most distinctive - but not a recognizable style of cutting - at least on drinking glasses - from the Regency years. Although this type of horizontal prismatic cutting appears on decanters of that period (and earlier), and perhaps a little later on some small custards, there's nothing that I can see showing it on drinking glass - it simply isn't a type of cutting that was used for that purpose.
It looks unusual, and I can't really suggest a date other than not before the last third of the C19 and probably not later than 1940. Cutting, which feels sharp to the touch, appears on glass over a long period of time - it seems to start to fall away after the beginnings of the use of acid to speed up the polishing of the cutting, around the 1920's, I believe.
The depression under the foot won't help to date, and it may have originated almost anywhere in Europe. You might consider if it has the striation marks on the bowl and foot, and it there are any stones/seeds and any sign of the rim blip where this was cut. Together with colour of the glass, these factors might suggest C19 rather than C20, possibly.
Perhaps Peter (oldglassman) will have a look please.