Freezing bonus? (5)
I believe the answer is:
icing
I believe this is a double definition.
'freezing' is the first definition.
(I know that icing is a type of freezing)
'bonus?' is the second definition.
(I've seen this before)
(Other definitions for icing that I've seen before include "Concreted sugar" , "unwelcome on aircraft" , "Sweet thing" , "piece of cake?" , "Sugar-coating" .)