Hurry round one wreck (4)
I believe the answer is:
ruin
'wreck' is the definition.
(I know this)
'hurry round one' is the wordplay.
'hurry' becomes 'run' (running is a kind of hurrying).
'round' means one lot of letters goes inside another.
'one' becomes 'I' (Roman numeral).
'run' enclosing 'i' is 'RUIN'.
(Other definitions for ruin that I've seen before include "Reduce to bankruptcy" , "financial hardship" , "Building remains" , "Utter destruction or downfall" , "Destroy or bankrupt" .)