Lethargy in a tie arranged round end of year (7)
I believe the answer is:
inertia
'lethargy' is the definition.
(thesaurus)
'in a tie arranged round end of year' is the wordplay.
'arranged' indicates anagramming the letters.
'round' indicates putting letters inside.
'end of' says to take the final letters.
The final letter of 'year' is 'r'.
'a'+'tie'='atie'
'atie' is an anagram of 'etia'.
'etia' going around 'r' is 'ertia'.
'in'+'ertia'='INERTIA'
(Other definitions for inertia that I've seen before include "Tendency to remain at rest or in steady motion" , "I earn it (anag.)" , "Passiveness" , "Disinclination to act" , "Immobility" .)