Place to order a Reuben (4)
I believe the answer is:
deli
'place to order a reuben' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for deli that I've seen before include "small food shop" , "Specialised food shop" , "Fine-food store" , "Specialist foodshop(abbr.)" , "part of supermarket" .)