Or else their woes worsen (9)
I believe the answer is:
otherwise
'or else' is the definition.
(I've seen this before)
'their woes worsen' is the wordplay.
'worsen' indicates anagramming the letters.
'their'+'woes'='theirwoes'
'theirwoes' anagrammed gives 'OTHERWISE'.
(Other definitions for otherwise that I've seen before include "Under different conditions" , "Alternatively" , "in different circumstances" , "In other respects or ways" , "Apart from that" .)