duplex vs half-mast

duplex

noun
  • A system of multiple thrust faults bounded above and below by a roof thrust and floor thrust. 

  • A cancellation combining a numerical cancellation with a second mark showing time, date, and place of posting. 

  • A double-stranded polynucleotide. 

  • A dwelling unit with two floors 

  • A throwing motion where two balls are thrown with one hand at the same time. 

  • A house made up of two dwelling units. 

adj
  • Having two floors 

  • Having two units, divisions, suites, apartments 

  • Having horizons with contrasting textures. 

  • Bidirectional (in two directions). 

verb
  • To make a series of duplex throws. 

  • To make duplex. 

  • To make into a duplex. 

half-mast

noun
  • The lowered position of any thing. 

  • The lowered position, half the height of a mast, at which a flag is flown when mourning, especially expressing respect for the dead. 

  • The state of being partially erect 

How often have the words duplex and half-mast occurred in a corpus of books? (source: Google Ngram Viewer )