Wobbles: support's abrupt, abrupt (7)
I believe the answer is:
teeters
'wobbles' is the definition.
(I've seen this in another clue)
'support's abrupt abrupt' is the wordplay.
I cannot really understand how this works, but
'support' could be 'tee' (tee is a kind of support) and 'tee' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
(Other definitions for teeters that I've seen before include "Wobbles, wavers" , "Seesaws on the edge" .)