Most respect a trainee officer (7)
I believe the answer is:
admiral
'officer' is the definition.
(admiral is a kind of officer)
'most respect a trainee' is the wordplay.
'most' means to remove the last letter.
'respect' becomes 'admire' (admiring is a kind of respecting).
'a trainee' becomes 'al' (I am not sure about this - if you are sure you should believe this answer much more).
'admire' with its final letter taken away is 'admir'.
'admir'+'al'='ADMIRAL'
Can you help me to learn more?
(Other definitions for admiral that I've seen before include "[NELSON] perhaps" , "Supreme naval commander" , "Eg, Nelson" , "Navy rank" , "Senior naval officer" .)