Platform said to be wobbly (4)
I believe the answer is:
dais
'platform' is the definition.
(I know that dais is a type of platform)
'said to be wobbly' is the wordplay.
'to be wobbly' indicates an anagram.
'said' with letters rearranged gives 'DAIS'.
(Other definitions for dais that I've seen before include "Speaker's raised platform" , "stand" , "device to give some an uplift at conference?" , "Platform, rostrum" , "stepping up here?" .)