I put on a different description of ideal world (7)
I believe the answer is:
utopian
'description of ideal world' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'i put on a different' is the wordplay.
'different' indicates anagramming the letters (letters placed in a different order).
'i'+'put'+'on'+'a'='iputona'
'iputona' with letters rearranged gives 'UTOPIAN'.
Can you help me to learn more?
(Other definitions for utopian that I've seen before include "Of ideal perfection (as More's state)" , "Ideal; imaginary" , "Idealistic reformer" , "Of Thomas More's perfect place" , "Unworkable" .)