Modern being on the money (6)
I believe the answer is:
recent
'modern' is the definition.
(I've seen this before)
'on the money' is the wordplay.
'on' becomes 're' ('on' can be mean 'with reference to').
'the money' becomes 'cent' (eg denomination of dollars).
're'+'cent'='RECENT'
'being' acts as a link.
(Other definitions for recent that I've seen before include "New, of late" , "Latest - current" , "Fresh, modern" , "Not long ago, just a little while past" , "Done not long ago" .)