Diagnostic test, possibly — botched after list oddly went missing (6)
I believe the answer is:
biopsy
'diagnostic test' is the definition.
'biopsy' can be an answer for 'test' (biopsy is a kind of test). I also know that 'diagnostic' relates to this answer.
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for biopsy that I've seen before include "Examination of tissues to determine disease" , "Examination of tissues or liquids from a living body" , "Microscopic test for disease" , "Examination of tissue taken from the body" , "Examination of tissue to determine the existence of disease" .)