Long angry speech from one in business (6)
I believe the answer is:
tirade
'long angry speech' is the definition.
(I've seen this before)
'one in business' is the wordplay.
'one' becomes 'i' (Roman numeral).
'in' indicates putting letters inside.
'business' becomes 'trade' (trade is a kind of business).
'i' placed within 'trade' is 'TIRADE'.
'from' acts as a link.
(Other definitions for tirade that I've seen before include "Vocal abuse" , "A long, abusive outburst" , "A tongue-lashing" , "Verbal broadside" , "A prolonged diatribe" .)