Outburst from upstanding character brought into commerce (6)
I believe the answer is:
tirade
'outburst' is the definition.
(I've seen this before)
'upstanding character brought into commerce' is the wordplay.
'upstanding character' becomes 'I' (vertical or upright letter or character).
'brought into' means one lot of letters goes inside another.
'commerce' becomes 'trade' (trade is a kind of commerce).
'i' going into 'trade' is 'TIRADE'.
'from' acts as a link.
(Other definitions for tirade that I've seen before include "A tongue-lashing" , "Prolonged speech of abuse" , "Torrent of abuse" , "Intemperate outburst" , "Sustained abuse" .)