letterbox vs pyx

letterbox

noun
  • A hidden container that holds a logbook and rubber stamp, found by following clues as a form of recreation. 

  • A rectangular hole or slot. 

  • A delivery point for mail, a box, compartment or slot for this purpose. 

  • A collection point for mail intended for onward delivery, a secure box or receptacle for this purpose. 

verb
  • To transfer a widescreen motion picture to home video formats while preserving the original aspect ratio, with the placing of black bars above and below the picture area. 

  • To hunt for letterboxes (containers with logbook and rubber stamp) by following clues. 

adj
  • Transferred to home video formats while preserving the original aspect ratio, having black bars above and below the picture area. 

pyx

noun
  • A (small) box; a casket, a coffret. 

  • A box used in a mint as a place to deposit sample coins intended to have the fineness of their metal and their weight tested before the coins are issued to the public. 

  • A small, usually round container used to hold the host (“consecrated bread or wafer of the Eucharist”), especially when bringing communion to the sick or others unable to attend Mass. 

verb
  • To enclose (something) in a box or other container; specifically, to place (a deceased person's body) in a coffin; to coffin, to encoffin. 

  • To deposit (sample coins) in a pyx; (by extension) to test (such coins) for the fineness of metal and weight before a mint issues them to the public. 

How often have the words letterbox and pyx occurred in a corpus of books? (source: Google Ngram Viewer )