Give in regarding period for abstinence (6)
I believe the answer is:
relent
'give in' is the definition.
(I've seen this before)
'regarding period for abstinence' is the wordplay.
'regarding' becomes 're'.
'period for abstinence' becomes 'lent'.
're'+'lent'='RELENT'
(Other definitions for relent that I've seen before include "Be merciful" , "Ease off" , "Relax severity or opposition" , "Become less intense" , "Back down" .)