Sincerely requested salary to cover royal education (6)
I believe the answer is:
prayed
'sincerely requested' is the definition.
The answer and definition can be both to do with communicating as well as being past participle verbs.
Perhaps there's an association between them I don't understand?
'salary to cover royal education' is the wordplay.
'salary' becomes 'pay' (synonyms).
'to cover' is an insertion indicator.
'royal' becomes 'r' (abbreviation).
'education' becomes 'ed' (abbreviation - e.g. sex ed).
'pay' enclosing 'r' is 'pray'.
'pray'+'ed'='PRAYED'
Can you help me to learn more?
(Other definitions for prayed that I've seen before include "Appealed to a deity" , "Addressed a deity" , "Made supplication to God" , "Addressed God" , "Worshipped" .)