Dictator's extremely tawdry wild speech (6)
I believe the answer is:
tyrant
'dictator's' is the definition.
(tyrant is a kind of dictator)
'extremely tawdry wild speech' is the wordplay.
'extremely' suggests removing the centre (only the extremes of the word are used).
'wild speech' becomes 'rant' (I've seen this before).
'tawdry' with its middle removed is 'ty'.
'ty'+'rant'='TYRANT'
(Other definitions for tyrant that I've seen before include "Martinet" , "Despotic ruler" , "Harsh and absolute ruler" , "Cruel and oppressive dictator" , "Oppressor" .)