Getting off to a late start spoils cricket session (7)
I believe the answer is:
innings
'cricket session' is the definition.
(innings is a division of a cricket game)
'getting off to a late start spoils' is the wordplay.
'getting off to a late start' means to remove the first letter (the letter which starts the word is ignored).
'spoils' becomes 'winnings' (I've seen this before).
'winnings' with its first letter taken away is 'INNINGS'.
(Other definitions for innings that I've seen before include "In which deliveries are received" , "Turns for the batsman" , "part of cricket match" , "Period at the wicket" , "knock" .)