Lazy type, terribly riled (5)
I believe the answer is:
idler
'lazy type' is the definition.
(I've seen this before)
'terribly riled' is the wordplay.
'terribly' is an anagram indicator.
'riled' anagrammed gives 'IDLER'.
(Other definitions for idler that I've seen before include "Work-shy individual" , "one averse to work" , "Person who does no work" , "One who doesn't want to work" , "Time waster" .)