A long angry speech - read it out (6)
I believe the answer is:
tirade
'a long angry speech?' is the definition.
(I've seen this before)
'read it out' is the wordplay.
'out' indicates an anagram (out can mean wrong or inaccurate).
'read'+'it'='readit'
'readit' with letters rearranged gives 'TIRADE'.
(Other definitions for tirade that I've seen before include "Torrent of abuse" , "Verbal onslaught" , "lecture" , "String of invective" , "Vocal abuse" .)