It's sometimes held at a deli (4)
I believe the answer is:
mayo
'it's sometimes held at a deli' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for mayo that I've seen before include "Eg, Braeburn or Cox" , "Irish county (county town, Castlebar)" , "Irish county; dressing" , "Thick creamy dressing" , "County of Western Eire" .)