About to happen as mischievous child gets close (9)
I believe the answer is:
impending
'about to happen' is the definition.
(I've seen this before)
'mischievous child gets close' is the wordplay.
'mischievous child' becomes 'imp' (I've seen this before).
'gets' says to put letters next to each other.
'close' becomes 'ending' ('ending' can be a synonym of 'close'**).
'imp'+'ending'='IMPENDING'
'as' is the link.
(Other definitions for impending that I've seen before include "About to happen" , "coming?" , "Threatening" , "Looming" .)