Poetic inactivity in Lidl (Essex) (7)
I believe the answer is:
idlesse
'poetic inactivity' is the definition.
(old-fashioned/poetic term for idleness)
'in lidl essex' is the wordplay.
'in' indicates the answer is hidden within the clue.
'IDLESSE' can be found hidden inside 'lidl essex'.
(Other definitions for idlesse that I've seen before include "sloth, as was" , "laziness" , "In poetry, indolence" .)