Amount it turned out giving change (8)
I believe the answer is:
mutation
'change' is the definition.
(mutation is a kind of change)
'amount it turned out' is the wordplay.
'turned out' indicates anagramming the letters.
'amount'+'it'='amountit'
'amountit' with letters rearranged gives 'MUTATION'.
'giving' is the link.
(Other definitions for mutation that I've seen before include "Change, especially biological or genetic" , "17 change in form" , "Change in genetic structure" , "Change in genetic material" , "Natural change process" .)