One working late has arranged own light (5,3)
I believe the answer is:
night owl
'one working late' is the definition.
(I've seen this before)
'arranged own light' is the wordplay.
'arranged' indicates anagramming the letters.
'own'+'light'='ownlight'
'ownlight' is an anagram of 'NIGHT-OWL'.
'has' is the link.
(Other definitions for night owl that I've seen before include "One likes to be active late into the evening" , "Churchill was one" , "One stays up late" , "Person and creature active after dark" , "Late sleeper" .)