Wobble being unwell during leave (9)
I believe the answer is:
vacillate
'wobble' is the definition.
(thesaurus)
'unwell during leave' is the wordplay.
'unwell' becomes 'i'll' (similar in meaning).
'during' is an insertion indicator.
'leave' becomes 'vacate' (to vacate a place is to leave it).
'ill' placed within 'vacate' is 'VACILLATE'.
'being' acts as a link.
(Other definitions for vacillate that I've seen before include "Dither" , "indecisive" , "Hesitate" , "Be in two minds" , "Keep changing one's mind" .)