Bunnies discovered jumping out of boredom (5)
I believe the answer is:
ennui
'boredom' is the definition.
(synonyms)
'bunnies discovered jumping' is the wordplay.
'discovered' says to take the centre (dis-covered - outer letters removed).
'jumping' indicates an anagram.
The centre of 'bunnies' is 'unnie'.
'unnie' with letters rearranged gives 'ENNUI'.
'out of' acts as a link.
(Other definitions for ennui that I've seen before include "Feeling of dissatisfaction" , "Boredom, tedium" , "Lack of interest" , "Boredom or discontent" , "Boredom, dullness" .)