Even nuisances can display boredom (5)
I believe the answer is:
ennui
'boredom' is the definition.
(I know that boredom can be written as ennui)
'even nuisances can display' is the wordplay.
'display' indicates a hidden word (I've seen 'displayed' mean this (the answer is displayed within the clue)).
'ENNUI' is hidden in the letters of 'even nuisances can'.
(Other definitions for ennui that I've seen before include "Boredom or discontent" , "depression" , "Weariness with life" , "Bored listlessness" , "Sense of tedium" .)