Someone who has quit company misusing HR time (6)
I believe the answer is:
hermit
'someone who has quit company' is the definition.
'hermit' can be an answer for 'someone' (hermit is a kind of someone). I am unsure of the rest of the definition.
'misusing hr time' is the wordplay.
'misusing' indicates anagramming the letters.
'hr'+'time'='hrtime'
'hrtime' is an anagram of 'HERMIT'.
Can you help me to learn more?
(Other definitions for hermit that I've seen before include "One lives in solitude for religious reasons" , "Solitary religious" , "Eremite" , "Liver in solitude" , "Person like Peter" .)