Jump over arched roof (5)
I believe the answer is:
vault
I believe this clue is a triple definition!
'jump' is the first definition.
(I know that vault is a more specific form of the action jump)
'over' is the second definition.
(thesaurus)
'arched roof' is the third definition.
(thesaurus)
(Other definitions for vault that I've seen before include "Where bodies may be kept" , "Secure room -- spring over" , "Bank's strongroom" , "Spring - clear - cellar" , "Leap - arched ceiling" .)