Song won't end in joy (6)
I believe the answer is:
shanty
'song' is the definition.
(I know that shanty is a type of work song)
'won't end in joy' is the wordplay.
'won't' becomes 'shan't' (I've seen this in another clue).
'end in' indicates one should take the final letters.
The last letter of 'joy' is 'y'.
'shant'+'y'='SHANTY'
(Other definitions for shanty that I've seen before include "Small crude shelter and sailor's song" , "A song for sailors or a ramshackle house" , "Here you get inferior accommodation" , "Sea song - hovel" , "Crude dwelling - sailor's song" .)