Greek letter about end of bailout is a disgrace (6)
I believe the answer is:
stigma
'a disgrace' is the definition.
(I've seen this before)
'greek letter about end of bailout' is the wordplay.
'greek letter' becomes 'sigma' (letter from the Greek alphabet).
'about' is an insertion indicator.
'end of' suggests the final letters.
The last letter of 'bailout' is 't'.
'sigma' enclosing 't' is 'STIGMA'.
'is' acts as a link.
(Other definitions for stigma that I've seen before include "Mark of dishonour" , "Symbol of disgrace or infamy" , "Brand or mark of infamy" , "Mark of shame or social disgrace" , "A stain as on character" .)