Brutally taser mad Leo, first, and wild Olive (8)
I believe the answer is:
oleaster
'wild olive' is the definition.
(I've seen this in another clue)
'brutally taser mad leo first' is the wordplay.
I cannot really see how this works, but
an anagram of 'taser' is 'aster' which is present in the answer.
an anagram of 'leo' is 'ole' which is present in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
'and' is the link.
Can you help me to learn more?
(Other definitions for oleaster that I've seen before include "Plant" , "One produces fruit" , "Tree" , "Shrub like an olive" , "Shrub; steel oar (anag.)" .)