Give way regarding period of abstinence (6)
I believe the answer is:
relent
'give way' is the definition.
(I've seen this in another clue)
'regarding period of abstinence' is the wordplay.
'regarding' becomes 're' ('re' means regarding or about).
'period of abstinence' becomes 'lent' (I've seen this in another clue).
're'+'lent'='RELENT'
(Other definitions for relent that I've seen before include "Become less stern than intended" , "Back down" , "Give in to influence or pressure" , "Become less severe, soften" , "Relax severity or opposition" .)