On the rocks in sun and air (9)
I believe the answer is:
insolvent
'on the rocks' is the definition.
(I've seen this before)
'in sun and air' is the wordplay.
'sun' becomes 'sol' (Latin for 'sun').
'and' means one lot of letters go next to another.
'air' becomes 'vent' (both can mean to express or reveal).
'in'+'sol'+'vent'='INSOLVENT'
(Other definitions for insolvent that I've seen before include "on the rocks" , "deep in debt?" , "without the means to pay" , "strapped for cash" , "In the red" .)