Wet person in debt included in cast (7)
I believe the answer is:
showery
'wet' is the definition.
(similar in meaning)
'person in debt included in cast' is the wordplay.
'person in debt' becomes 'ower' (someone who owes money).
'included in' indicates putting letters inside.
'cast' becomes 'shy' (I've seen this before).
'ower' put into 'shy' is 'SHOWERY'.
(Other definitions for showery that I've seen before include "some rain" , "Like many British days" , "Raining intermittently" , "far from fine" , "Wet" .)