The meaning of 'Abbey' is a type of decorative ware that S&W produced. Both the references that I gave in my last post show Abbey Ware.
So, as Christine rightly points out the crackle effect on the surface, which was introduced a month after the colour only version, in April 1928 (This is similar to Monart's Cloisonne ware, or S&W's Arabesque). The colour only, is large-ish areas of enamel/colour used to make the desired decorative effect - introduced March 1928.
As far as I'm aware at the moment there is no known derivation/reason for the name 'Abbey' being used.