There are actually debates about what is the difference between pocketbook and purse. Interestingly, the difference seems more evident through different generations and regions: simply a variation word choice as opposed to a real variation bag. The differences can also be according to the size of the bag. Still, there might be others who use the terms depending on the time of day. Let’s see the following differences:
This is where the discussion vs pocket bag really gets confusing. Some will say that a bag is small and is used to carry notes and coins maybe an abbreviated term “coin purse”. A pocketbook, then, is a bag in which to carry purse. Many others, however, say that a pocketbook is smaller, not necessarily small enough to fit in a pocket, but smaller than a purse and is used more as a wallet or clutch. A purse, then, can also become a bag large enough to carry pocketbook inside.
– Time of Day
Some women think of pocketbook as their “day” bag and purse as their “evening” bag. It would seem that both words can even be applied to the same bag depending on the time of day.
There are always exceptions, of course, but speaking about this in general, the northeastern and southeastern regions of the United States offer the greatest use of the term pocketbook. Meanwhile, the more common term remains across the western, southwestern and midwestern regions is purse.
Although “official” language research shows investigation of language use of pocketbook and purse is spread fairly even across generations, the general consensus in forums and similar point of “pocketbook” being more old-fashioned and antiquated term. However, a word that sounds old-fashioned, does not mean it is not used regularly. In any case, many actually favor the word because of its ancient period and classic touch. In general, however, younger generations tend to favor the words “purse” or simply “bag”.