Shaky United Nations' record (8)
I believe the answer is:
unstable
'shaky' is the definition.
('unstable' can be similar in meaning to 'shaky')
'united nations' record' is the wordplay.
'united nations'' becomes 'uns' ('UN' can be a synonym of 'united nations').
'record' becomes 'table' (I've seen this before).
'uns'+'table'='UNSTABLE'
(Other definitions for unstable that I've seen before include "lacking security" , "Ban lutes (anag.)" , "Not well-balanced, liable to wobble" , "Likely to collapse" , "Not steady, maybe irrational" .)