Limitless cash, money, used in rise (6)
I believe the answer is:
ascent
'rise' is the definition.
(I know that rise can be written as ascent)
'limitless cash money' is the wordplay.
'limitless' says to take the centre.
'money' becomes 'cent' (eg denomination of dollars).
The centre of 'cash' is 'as'.
'as'+'cent'='ASCENT'
'used in' acts as a link.
(Other definitions for ascent that I've seen before include "The climbing of a peak" , "Maybe promotion" , "Enacts in climb" , "Upward climb" , "Incline" .)