Figure in clothing for hockey showing cheek in post-match activity (12)

'post-match activity' is the definition.
I can't judge whether this defines the answer.

'figure in clothing for hockey showing cheek' is the wordplay.
'figure' becomes 'one' (a numerical figure).
'in' indicates putting letters inside.
'clothing for' means to remove the middle letters (only the letters which clothe the word).
'showing cheek' becomes 'mooning' (I can't explain this - if you can you should give a lot more credence to this answer).
'hockey' with its middle taken out is 'hy'.
'one' inserted into 'hy' is 'honey'.
'honey'+'mooning'='HONEYMOONING'

'in' acts as a link.

Can you help me to learn more?