Pass mark (5)
I believe the answer is:
cross
I believe this clue is a double definition.
'pass' is the first definition.
(crossing is a kind of passing)
'mark' is the second definition.
('cross' can be a synonym of 'mark')
(Other definitions for cross that I've seen before include "Symbol of Christianity" , "Mongrel" , "Short punch in boxing" , "frustrated?" , "Rood - intersect - annoyed" .)