Slave’s extremely horrible fate (5)
I believe the answer is:
helot
'slave's' is the definition.
(slave in ancient Sparta)
'extremely horrible fate' is the wordplay.
'extremely' says to hollow out the word (remove centre letters) (only the extremes of the word are used).
'fate' becomes 'lot' (synonyms).
'horrible' with its middle removed is 'he'.
'he'+'lot'='HELOT'
(Other definitions for helot that I've seen before include "downtrodden?" , "Spartan serf" , "One made to work" , "Spartan slave" , "He's bound to land" .)