Spread out terribly impressed, having lost millions (8)
I believe the answer is:
disperse
'spread out' is the definition.
('disperse' can be a synonym of 'spread out')
'terribly impressed having lost millions' is the wordplay.
'terribly' indicates anagramming the letters.
'having lost' is a deletion indicator.
'millions' becomes 'm' (abbreviation).
'impressed' with 'm' taken away is 'ipressed'.
'ipressed' is an anagram of 'DISPERSE'.
(Other definitions for disperse that I've seen before include "Scatter, break up" , "'Break up, spread out (8)'" , "Broadcast" , "Break up, move away from each other" , "Spread widely" .)