Eats in mess for tea (6)
I believe the answer is:
tisane
'tea' is the definition.
(tisane is a kind of tea)
'eats in mess' is the wordplay.
'mess' indicates anagramming the letters.
'eats'+'in'='eatsin'
'eatsin' with letters rearranged gives 'TISANE'.
'for' is the link.
(Other definitions for tisane that I've seen before include "relaxing drink" , "Herb tea" , "Herbal infusion" , "Herb-tea" , "Infusion of e.g. dried or fresh flowers or leaves" .)