Rather tasteless savage upsetting lead character (4)
I believe the answer is:
mild
'rather tasteless' is the definition.
'mild' can be an answer for 'tasteless' (thesaurus). I am not sure about the 'rather' bit.
'savage upsetting lead character' is the wordplay.
'savage upsetting lead' becomes 'mil' (I can't explain this - if you can you should give a lot more credence to this answer).
'character' becomes 'd'.
'mil'+'d'='MILD'
Can you help me to learn more?
(Other definitions for mild that I've seen before include "Not intense; beer" , "Far from extreme" , "Gentle in temper and disposition" , "Calm" , "Clement -- type of beer" .)