Overlooked auditor's purchase history (8)
I believe the answer is:
bypassed
'overlooked' is the definition.
Although both the answer and definition are past participle verbs, I cannot see how one could define the other.
'auditor's purchase history' is the wordplay.
'auditor's' indicates a 'sounds like' (homophone) clue.
'purchase' becomes 'buy' (buy is a kind of purchase).
'history' becomes 'passed' (I can't justify this - if you can you should give a lot more credence to this answer).
'buy' sounds like 'by'.
'by'+'passed'='BYPASSED'
Can you help me to learn more?
(Other definitions for bypassed that I've seen before include "Ignored" , "Avoided (a town or city)" , "Diverted, went around" , "Went around, town or heart" .)