Legal official’s polite refusal on track (6)
I believe the answer is:
notary
'legal official's' is the definition.
(I've seen this before)
'polite refusal on track' is the wordplay.
'polite refusal' becomes 'nota' (I can't justify this - if you can you should believe this answer much more).
'on' means one lot of letters go next to another (in a down clue, letters appear on others).
'track' becomes 'ry' (abbreviation for railway).
'nota'+'ry'='NOTARY'
Can you help me to learn more?
(Other definitions for notary that I've seen before include "legal worker" , "Person authorised to certify legal documents" , "Public records official" , "Official working on legal documents" , "Certifier of deeds etc." .)