Show of hesitation by English dog trader (1-6)
I believe the answer is:
e tailer
'trader' is the definition.
(I have seen 'Modern trader' mean 'e tailer' so perhaps 'trader' could also mean 'e tailer')
'show of hesitation by english dog' is the wordplay.
'show of hesitation' becomes 'er' (I've seen this in other clues).
'by' means one lot of letters go next to another.
'english' becomes 'E' (abbreviation).
'dog' becomes 'tail' (synonyms).
'e'+'tail'='etail'
'er' after 'etail' is 'E-TAILER'.
(Other definitions for e tailer that I've seen before include "online seller" , "internet business" , "internet seller" , "Modern trader" , "... businessman here [THE NET]" .)