One that can be let off employment after sack (8)
I believe the answer is:
firework
'one that can be let' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'employment after sack' is the wordplay.
'employment' becomes 'work' (synonyms).
'after' is a charade indicator (letters next to each other).
'sack' becomes 'fire' (both can mean to dismiss from a job).
'work' after 'fire' is 'FIREWORK'.
'off' acts as a link.
Can you help me to learn more?
(Other definitions for firework that I've seen before include "rocket" , "fountain, say" , "Banger, for example" , "Pyrotechnic device" , "Colourful incendiary device used for entertainment" .)