Six embroiled in the Spanish wickedness (4)
I believe the answer is:
evil
'wickedness' is the definition.
(I know that wickedness can be written as evil)
'six embroiled in the spanish' is the wordplay.
'six' becomes 'VI' (Roman numerals).
'embroiled in' means one lot of letters goes inside another.
'the spanish' becomes 'el' ('the' in Spanish).
'vi' going inside 'el' is 'EVIL'.
(Other definitions for evil that I've seen before include "Profoundly immoral" , "Profoundly malevolent" , "Badness, depravity" , "Morally objectionable behavior" , "Depraved" .)