Tube taken by someone who needs to rush off (5)
I believe the answer is:
baton
'tube taken by someone who needs to rush off' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'tube taken by' is the wordplay.
'tube' becomes 'bon' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'taken' is an insertion indicator.
'by' becomes 'at'.
'bon' going around 'at' is 'BATON'.
(Other definitions for baton that I've seen before include "one watched by players" , "Policeman's truncheon" , "Short rod (that can be passed!)" , "A conductor wields it - or a policemen" , "Conductor wields it - or a policeman" .)