Problem, snag (5)
I believe the answer is:
hitch
I believe this is a double definition.
'problem' is the first definition.
(a hitch is a problem or difficulty)
'snag' is the second definition.
(synonyms)
(Other definitions for hitch that I've seen before include "Hindrance" , "Pull up" , "Unexpected problem" , "Temporary obstacle" , "get a free ride" .)