Contrary to how nerve is broken (7)
I believe the answer is:
inverse
'contrary' is the definition.
(I've seen this before)
'nerve is broken' is the wordplay.
'broken' indicates anagramming the letters.
'nerve'+'is'='nerveis'
'nerveis' with letters rearranged gives 'INVERSE'.
'to how' acts as a link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for inverse that I've seen before include "Transposed" , "Contrary in effect" , "Reversed in position like enviers" , "Opposite in direction" , "Something the exact opposite of another" .)