Yours truly wrestling endless sloth (8)
I believe the answer is:
idleness
'sloth' is the definition.
(thesaurus)
'yours truly wrestling endless' is the wordplay.
'yours truly' becomes 'i'.
'wrestling' indicates anagramming the letters.
'endless' anagrammed gives 'dleness'.
'i'+'dleness'='IDLENESS'
(Other definitions for idleness that I've seen before include "pansy growers find love in?" , "State of doing nothing" , "I'm having nothing to do" , "Send lies (anag.)" , "unemployment" .)