At the home of companion, meze is limitless (4)
I believe the answer is:
chez
'at the home' is the definition.
(I've seen this before)
'companion meze is limitless' is the wordplay.
'companion' becomes 'ch' (Companion of Honour).
'is limitless' says to take the centre.
The central letters of 'meze' are 'ez'.
'ch'+'ez'='CHEZ'
'of' is the link.
(Other definitions for chez that I've seen before include "At French house, maybe moi" , "At the French home of - moi?" , "At the home of - in France" , "A French house, may be moi" .)