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 in another clue)
'read it out' is the wordplay.
'out' indicates an anagram (out can mean wrong or inaccurate).
'read'+'it'='readit'
'readit' anagrammed gives 'TIRADE'.
(Other definitions for tirade that I've seen before include "Torrent of abuse" , "Verbal onslaught" , "lecture" , "String of invective" , "Vocal abuse" .)