He composed short part of speech I had misdirected (5)
I believe the answer is:
verdi
'he composed' is the definition.
(composer Giuseppe Verdi)
'short part of speech i had misdirected' is the wordplay.
'short' means to remove the last letter.
'part of speech' becomes 'verb' (verb is a kind of part of speech).
'i had' becomes 'id' (common contraction).
'misdirected' shows that the letters should be reversed in order (letters go in the wrong direction).
'id' back-to-front is 'di'.
'verb' with its final letter taken off is 'ver'.
'ver'+'di'='VERDI'
(Other definitions for verdi that I've seen before include "Composer of the operas Macbeth, Falstaff" , "Composer of opera ''Rigoletto''" , "Giuseppe -----, 1813-1901, prolific opera composer" , "note writer" , "Drive around to locate opera composer" .)