Admirer pinching bottom? He rectifies errors (9)
I believe the answer is:
subeditor
'he rectifies errors' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'admirer pinching bottom?' is the wordplay.
'admirer' becomes 'suitor' (suitor is a kind of admirer).
'pinching' is an insertion indicator (taking inside).
'bottom?' becomes 'bed' (synonyms).
'suitor' placed around 'bed' is 'SUBEDITOR'.
Can you help me to learn more?
(Other definitions for subeditor that I've seen before include "Reviser" , "One proof-reads writers' copy" , "one makes the headlines" , "Newspaper employee" , "News employee" .)