Slob finally agreed extra runs (4)
I believe the answer is:
byes
'extra runs' is the definition.
(cricket)
'slob finally agreed' is the wordplay.
'finally' indicates one should take the final letters.
'agreed' becomes 'yes' (I've seen this before).
The final letter of 'slob' is 'b'.
'b'+'yes'='BYES'
(Other definitions for byes that I've seen before include "Runs not from bat" , "Wicketkeeper's concession" , "Runs wicketkeeper concedes" , "Extra runs" , "In cricket, runs scored from balls that pass the batman without being hit" .)