Qualify? I don't know (4)
I believe the answer is:
pass
I believe this clue is a double definition.
'qualify?' is the first definition.
(thesaurus)
'i don't know' is the second definition.
(I've seen this before)
(Other definitions for pass that I've seen before include "change" , "complimentary ticket" , "Hand over < identity card" , "Get through exam" , "Overtake; mountain way" .)