Almost yearn for leader's shenanigans (8)
I believe the answer is:
mischief
'shenanigans' is the definition.
(I've seen this before)
'almost yearn for leader's' is the wordplay.
'almost' means to remove the last letter (almost the whole word is kept).
'yearn for' becomes 'miss' (I've seen this in another clue).
'leader' becomes 'chief' (chief is a kind of leader).
'miss' with its final letter taken away is 'mis'.
'mis'+'chief'='MISCHIEF'
(Other definitions for mischief that I've seen before include "bad behaviour" , "nuisance" , "Monkey business" , "Hanky-panky" , "Reckless behaviour" .)