Cash immediately available (5)
I believe the answer is:
ready
This might be a double definition.
'cash immediately' is the first definition.
'ready' can be an answer for 'cash' (ready can informally refer to cash). I'm not certain of the 'immediately' bit.
'available' is the second definition.
(similar in meaning)
Can you help me to learn more?
(Other definitions for ready that I've seen before include "game?" , "Cash; within reach" , "Suitably prepared" , "Prepare money" , "rough companion" .)