Food for chaps in a mess (7)
I believe the answer is:
spinach
'food' is the definition.
(spinach is a kind of food)
'chaps in a mess' is the wordplay.
'a mess' indicates an anagram.
'chaps'+'in'='chapsin'
'chapsin' anagrammed gives 'SPINACH'.
'for' is the link.
(Other definitions for spinach that I've seen before include "Vegetable, source of iron" , "Dark green vegetable" , "something to eat" , "Leafy vegetable" , "Popeye the Sailor's vegetable of choice" .)