One hurried round in the wet (4)
I believe the answer is:
rain
'the wet' is the definition.
(the wet can mean wet weather)
'one hurried round' is the wordplay.
'one' becomes 'i' (Roman numeral).
'hurried' becomes 'ran' (running is a kind of hurrying).
'round' means one lot of letters goes inside another.
'i' placed within 'ran' is 'RAIN'.
'in' acts as a link.
(Other definitions for rain that I've seen before include "previous rule?" , "Wet weather" , "downfall?" , "eg A shower" , "Come down in showers" .)