Worked in kitchen, lacking any energy (6,2)
I believe the answer is:
washed up
I believe this clue is a double definition.
'worked in kitchen' is the first definition.
(washing up is done in the kitchen)
'lacking any energy' is the second definition.
(washed-up can mean weak or ineffective)
(Other definitions for washed up that I've seen before include "Did kitchen duty" , "Carried ashore by the tide" , "Cleaned plates etc." , "No longer successful (colloq.)" , "Finished (the dishes?)" .)