Inclined afterwards to improve — looking tired initially (5)
I believe the answer is:
atilt
'inclined' is the definition.
(similar in meaning)
'afterwards to improve looking tired initially' is the wordplay.
'initially' says to take the initial letters.
The first letters of 'afterwards to improve looking tired' is 'ATILT'.
(Other definitions for atilt that I've seen before include "Listing" , "Leaning over and nearly falling" , "Inclined" , "Pulled tight" , "Hardly straight" .)