Definition from Wiktionary, the free dictionary
The sense of store much more recent, originating in ellipsis from the common attributive use, as in delicatessen shop, delicatessen store, etc.
delicatessen (plural delicatessens)
- (countable) A shop that sells cooked or prepared foods ready for serving.
- (plural only) Delicacies; exotic or expensive foods.
shop selling prepared foods