Shilling in kitty for stake (4)
I believe the answer is:
post
'stake' is the definition.
(I've seen this before)
'shilling in kitty' is the wordplay.
'shilling' becomes 's'.
'in' indicates putting letters inside.
'kitty' becomes 'pot' ('pot' can be a synonym of 'kitty').
's' going within 'pot' is 'POST'.
'for' acts as a link.
(Other definitions for post that I've seen before include "Stake; appointment" , "Mail; wooden stake" , "Station" , "Publicly display; send" , "ob" .)