Really cool places in one top-class revolutionary space (7)
I believe the answer is:
icecaps
'really cool places' is the definition.
Although both the answer and definition are plural nouns, I can't see how they can define each other.
'one top-class revolutionary space' is the wordplay.
'one' becomes 'I' (Roman numeral).
'top' suggests taking the first letters.
'revolutionary' shows that the letters should be reversed in order.
The initial letter of 'class' is 'c'.
'space' written backwards gives 'ecaps'.
'i'+'c'+'ecaps'='ICECAPS'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for icecaps that I've seen before include "Glacial areas" , "White sheets" , "objects being eliminated from the world" , "Areas of permanent glaciation" , "Cold headgear, perhaps?" .)