Holy Communion finally secure (3)

I believe the answer is:

'secure' is the definition.
(pinning is a kind of securing)

'holy communion finally' is the wordplay.
'holy' becomes 'pi' (I've seen this in other clues).
'finally' indicates one should take the final letters.
The final letter of 'communion' is 'n'.
'pi'+'n'='PIN'

(Other definitions for pin that I've seen before include "form of identification" , "Small object to fasten or attach" , "Skittle; fix" , "Small brooch; skittle" , "leg" .)

I've seen this clue in The Guardian.

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