No good going in without answer ready (5)
I believe the answer is:
wonga
'ready' is the definition.
(both are slang terms for money)
'no good going in without answer' is the wordplay.
'no' becomes 'n' (common abbreviation).
'good' becomes 'g' (abbreviation).
'going in' indicates putting letters inside.
'without' becomes 'wo' (abbreviation of 'without', normally with a slash**).
'answer' becomes 'a' (abbreviation eg in Q and A).
'n'+'g'='ng'
'wo'+'a'='woa'
'ng' placed into 'woa' is 'WONGA'.
(Other definitions for wonga that I've seen before include "Money (slang)" , "bread" , "Money (informal)" , "Lolly" , "Money (sl.)" .)