Fatigue of current head on display (9)
I believe the answer is:
weariness
'fatigue' is the definition.
(feeling fatigued or weary)
'of current head on display' is the wordplay.
'of current' becomes 'i' (I can't justify this - if you can you should believe this answer much more).
'head' becomes 'ness' (ness is a headland).
'on' means one lot of letters go next to another.
'display' becomes 'wear' (I've seen this in other clues).
'i'+'ness'='iness'
'iness' after 'wear' is 'WEARINESS'.
(Other definitions for weariness that I've seen before include "Fatigue, tiredness" , "Tired feeling" , "Lack of energy" , "State of fatigue or utter boredom" , "Lassitude" .)