The Collaborative International Dictionary of English v.0.48:

Trajection \Tra*jec"tion\, n. [L. trajectio a crossing over,
   transposition.]
   1. The act of trajecting; a throwing or casting through or
      across; also, emission. --Boyle.
      [1913 Webster]

   2. Transposition. [R.] --Knatchbull.
      [1913 Webster]