Hidden danger that may trap miners (7)
I believe the answer is:
pitfall
'hidden danger that' is the definition.
'pitfall' can be an answer for 'hidden danger' (pitfalls are unexpected dangers). I'm unsure of the remainder of the definition.
'trap miners' is the wordplay.
'trap' becomes 'pit' (pit is a kind of trap).
'miners' becomes 'fall' (I can't justify this - if you can you should give a lot more credence to this answer).
'pit'+'fall'='PITFALL'
'may' is the link.
Can you help me to learn more?
(Other definitions for pitfall that I've seen before include "Hazard" , "Unexpected difficulty or danger" , "Trap in the form of a concealed hole" , "Hidden danger or difficulty" , "Unexpected problem" .)