auditor
Concise Oxford English Dictionary © 2008 Oxford University Press:
auditor/ˈɔːdɪtə(r)/
▶noun
- 1 a person who conducts an audit.
- 2 a listener.
- 3 N. Amer. a person who attends a class informally without working for credit.
– derivatives
auditorial adjective.
auditorial adjective.
'auditor' also found in these Oxford entries:

