Flabby oaf the soup upset (3,2,5)
I believe the answer is:
out of shape
'flabby' is the definition.
(I've seen this in another clue)
'oaf the soup upset' is the wordplay.
'upset' is an anagram indicator.
'oaf'+'the'+'soup'='oafthesoup'
'oafthesoup' is an anagram of 'OUT OF SHAPE'.
(Other definitions for out of shape that I've seen before include "Whence military orders may come" , "Unfit" , "in poor condition" , "Unhealthy" , "Not fit" .)