Bag runs if brought up in reserve or give up? (9)
I believe the answer is:
sacrifice
'give up?' is the definition.
(sacrificing is a kind of giving up)
'bag runs if brought up in reserve' is the wordplay.
'bag' becomes 'sac' (I've seen this before).
'runs' becomes 'r' (cricket abbreviation**).
'brought up' says the letters should be written backwards (down clues only).
'in' is an insertion indicator.
'reserve' becomes 'ice' (I've seen this before).
'if' reversed gives 'fi'.
'fi' put into 'ice' is 'ifice'.
'sac'+'r'+'ifice'='SACRIFICE'
'or' is the link.
(Other definitions for sacrifice that I've seen before include "Offering to a god" , "Killed offering to a deity" , "Destroy" , "Immolate" , "Ritual killing" .)