Reserve first class fare that's frozen (3,5)
I believe the answer is:
ice cream
'fare that's frozen' is the definition.
I can't judge whether this definition defines the answer.
'reserve first class' is the wordplay.
'reserve' becomes 'ice ' (both can mean aloofness).
'first' means one lot of letters go next to another.
'class' becomes 'cream' (cream is a kind of class).
'ice'+'cream'='ICE-CREAM'
Can you help me to learn more?
(Other definitions for ice cream that I've seen before include "Gelato-like dessert" , "Cool confection, sweet frozen dessert" , "Party food" , "Dairy dessert" , "cone?" .)