Elastic gets old for uniform, a worry for security guard? (7)
I believe the answer is:
robbery
'guard?' is the definition.
The definition and answer can be both acts as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for robbery that I've seen before include "Theft maybe with violence" , "Theft crime" , "Theft, stealing" , "Theft of property" , "Criminal action" .)