Show round a number in the depot (11)
I believe the answer is:
ostentation
'show' is the definition.
(I've seen this before)
'round a number in the depot' is the wordplay.
'round' becomes 'o' (round can mean a round object).
'a number' becomes 'ten' (ten is a number).
'in' indicates putting letters inside.
'the depot' becomes 'station' (I've seen this before).
'ten' inserted inside 'station' is 'stentation'.
'o'+'stentation'='OSTENTATION'
(Other definitions for ostentation that I've seen before include "Pretentious display" , "Showiness" , "show" .)