Definition of red letter in English:

red letter


  • 1A character or word written or printed in red, typically in order to draw attention to particularly important or significant information. Chiefly in plural.

  • 2A small moth, Agonopterix ocellana (family Oecophoridae), of Eurasia and North Africa, having a white spot ringed with red in the centre of the pale forewing. Also "red-letter flat-body". rare.


Late Middle English; earliest use found in John Trevisa (c1342–?1402), translator. From red + letter.


red letter

/ˌrɛd ˈlɛtə/