Bit of pen point leaked (7)
I believe the answer is:
nibbled
'bit' is the definition.
(nibbling is a kind of biting)
'pen point leaked' is the wordplay.
'pen point' becomes 'nib' (the point of a pen).
'leaked' becomes 'bled' (bleed can mean to leak).
'nib'+'bled'='NIBBLED'
'of' is the link.
(Other definitions for nibbled that I've seen before include "Took small bites; ate intermittently" , "Bit off very small pieces" , "Ate sparingly" , "Took tiny bites" , "Gnawed" .)