Empty beer containers for these traders? (7)
I believe the answer is:
brewers
'these traders?' is the definition.
(people who sell beer)
'empty beer containers' is the wordplay.
'empty' means to remove the middle letters.
'containers' becomes 'ewers' (ewer is a kind of container).
'beer' with its middle taken out is 'br'.
'br'+'ewers'='BREWERS'
'for' is the link.
(Other definitions for brewers that I've seen before include "those providing drinks" , "A lexicographer's" , "They provide ales" , "Providers of ale" , "suppliers of liquid refreshment" .)