I don't know what will get me through security (4)
I believe the answer is:
pass
'i don't know' is the definition.
(e.g. response in a quiz)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for pass that I've seen before include "acceptable exam result" , "Exceed; mountain route" , "Exam success" , "Overtake; permit" , "sticky situation if one is pretty" .)