Observe item with a strap (5)
I believe the answer is:
watch
I believe this clue is a double definition.
'observe' is the first definition.
(I know that observe can be written as watch)
'item with a strap' is the second definition.
(eg a wrist watch has a strap)
(Other definitions for watch that I've seen before include "period of duty" , "Observe - timepiece" , "Observe - guard" , "Keep under observation" , "Timepiece - look out" .)