Piercing Spartacus initially with spear (8)
I believe the answer is:
strident
'piercing' is the definition.
(thesaurus)
'spartacus initially with spear' is the wordplay.
'spartacus initially' becomes 's' (I can't explain this - if you can you should give a lot more credence to this answer).
'with' is a charade indicator (letters next to each other).
'spear' becomes 'trident' (trident is a kind of spear).
's'+'trident'='STRIDENT'
Can you help me to learn more?
(Other definitions for strident that I've seen before include "harsh sound" , "ear-piercing" , "Roaring" , "making a lot of noise" , "Noisy" .)