The cost of cigarettes? (6)
I believe the answer is:
packet
This could be a double definition.
'the cost' is the first definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'of cigarettes?' is the second definition.
The definition suggests a singular noun which matches the answer.
Can you help me to learn more?
(Other definitions for packet that I've seen before include "Mailboat; item of mail" , "Container - ship" , "Small fortune - carton" , "bomb" , "Small parcel" .)