Yearning for a letter from the land of the Magyars (6)
I believe the answer is:
hungry
'yearning' is the definition.
(thesaurus)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for hungry that I've seen before include "hoping for a bite?" , "Peckish" , "Needing food" , "Short of food" , "Desiring food" .)