DEAD LETTER as NOUN

1. Meaning
   • mail that can neither be delivered nor returned
   Synonym(s)
   • dead mail (what does dead mail mean?)
   Hypernyms(s) dead letter is a kind of… Example: animal is a hypernym of mammal, plant is a hypernym of flower
   • letter (what does letter mean?)
   • missive (what does missive mean?)
2. Meaning
   • the state of something that has outlived its relevance
   Synonym(s)
   • non-issue (what does non-issue mean?)
   Hypernyms(s) dead letter is a kind of… Example: animal is a hypernym of mammal, plant is a hypernym of flower
   • state (what does state mean?)