'Osaka loot'? Dictionary essentially right (6)

I believe the answer is:

senior

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''osaka' is the definition.
I can't judge whether this definition defines the answer.

'loot'? dictionary essentially right' is the wordplay.
'loot'?' becomes 'sen' (I can't explain this - if you can you should believe this answer much more).
'essentially' says to take the centre.
'right' becomes 'r' (common abbreviation).
The centre of 'dictionary' is 'io'.
'sen'+'io'+'r'='SENIOR'

Can you help me to learn more?

(Other definitions for senior that I've seen before include "Superior - elder" , "Pupil in a higher form" , "'Older, superior (6)'" , "High-ranking" , "High in rank" .)

I've seen this clue in the Sydney Morning Herald.

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