Learnt letters from letter's returns (6)
I believe the answer is:
rental
'learnt letters from letter's returns' is the definition.
The answer and definition are not the same part of speech. However, past participle verbs and adjectives can sometimes mean the same thing.
'learnt letters' is the wordplay.
'letters' is an anagram indicator.
'learnt' is an anagram of 'RENTAL'.
Can you help me to learn more?
(Other definitions for rental that I've seen before include "Learnt (anag) -- lease" , "What's offered by a letter" , "4 across (anag)" , "money for landlord" , "Money paid for hire" .)