Assistant nonetheless gets energy lozenge (8)
I believe the answer is:
pastille
'lozenge' is the definition.
(pastille is a kind of lozenge)
'assistant nonetheless gets energy' is the wordplay.
'assistant' becomes 'pa' (personal assistant).
'nonetheless' becomes 'still' ('still' can be a synonym of 'nonetheless').
'gets' is a charade indicator (letters next to each other).
'energy' becomes 'e' (physics symbol as in E=mc2).
'pa'+'still'+'e'='PASTILLE'
(Other definitions for pastille that I've seen before include "Small, often medicated, sweet" , "Small sweet/lozenge" , "drop" , "something for a sore throat" , "Lozenge, to soothe the throat perhaps" .)