What is "trajection"

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.

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

n. 1 (context archaic English) The act of trajecting; a throwing or casting through or across; also, emission. 2 (context archaic English) transposition