Long speech: read it out (6)
I believe the answer is:
tirade
'long speech' is the definition.
'tirade' can be an answer for 'speech' (I have seen 'Angry speech' mean 'tirade' so perhaps 'speech' could also mean 'tirade'). I'm not certain of the 'long' bit.
'read it out' is the wordplay.
'out' is an anagram indicator (out can mean wrong or inaccurate).
'read'+'it'='readit'
'readit' is an anagram of 'TIRADE'.
Can you help me to learn more?
(Other definitions for tirade that I've seen before include "Blast of criticism" , "A tongue-lashing" , "strong words" , "Flow of invective" , "Prolonged abusive speech" .)