Shining up penal reform (9)

I believe the answer is:

punishing

I'm a little stuck... Click here to teach me more about this clue!

'penal reform' is the definition.
Although both the answer and 'reform' are verbs, they are not in the same form of the verb.

'shining up' is the wordplay.
'shining up' anagrams to 'PUNISHING'.
Though, I am not clear how this is indicated.

Can you help me to learn more?

(Other definitions for punishing that I've seen before include "Imposing a penalty or sanction" , "Harshly treating" , "taxing" .)

I've seen this clue in The Irish Independent.

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