Rat trap? (4)
I believe the answer is:
maze
'rat trap?' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for maze that I've seen before include "there's no obvious exit from this" , "Puzzling network of paths" , "Complex set of paths" , "Labyrinth, tangle" , "It's easy to get lost in one" .)