He hopes to dismiss bid involving partners in deal storing access code (3,7)

'he hopes to dismiss' is the definition.
(bowler hoping to dismiss a batsman in cricket)

'bid involving partners in deal storing access code' is the wordplay.
'bid' becomes 'offer' (synonyms).
'involving' is an insertion indicator.
'partners in deal' becomes 'SN' (South and North are partners in bridge).
'storing' indicates putting letters inside.
'access code' becomes 'PIN' (PIN number).
'sn' going around 'pin' is 'spinn'.
'offer' going around 'spinn' is 'OFF-SPINNER'.