Came down after siesta, subdued (10)
I believe the answer is:
restrained
'subdued' is the definition.
(similar in meaning)
'came down after siesta' is the wordplay.
'came down' becomes 'rained' (raining is a kind of coming down).
'after' means one lot of letters go next to another.
'siesta' becomes 'rest' (I've seen this in another clue).
'rained' put after 'rest' is 'RESTRAINED'.
(Other definitions for restrained that I've seen before include "Being limited" , "Reserved, dispassionate" , "Held back" , "subdued" , "Deprived of freedom" .)