Given a free passage? (9)

I believe the answer is:

unimpeded

I'm a little stuck... Click here to teach me more about this clue!

'free passage?' is the definition.
'unimpeded' can be an answer for 'free' (thesaurus). I am not sure about the 'passage?' bit.

I don't understand the remainder of the clue.

Can you help me to learn more?

(Other definitions for unimpeded that I've seen before include "Without let or hindrance" , "Not hindered or blocked" , "not delayed" , "Without check or obstruction" .)

I've seen this clue in The Globe and Mail.

Want a hint initially instead of a full solution? Install my app