noun

• (obsolete) A journey, way.
  "The holy gost before vs glad / ffull softly on his sithe"
• (obsolete) One's journey of life, experience, one's lot, also by extension life, lifetime.
  "Christ's sith of sorrow and suffering."
• (obsolete) An instant in time, a point in time or an occasion.
  "Of them the other philosophers have, by siths, taken their beginning."

noun

• (Star Wars) One of a fictional order of creatures from the Star Wars universe who represent the antithesis and ancient enemies of the Jedi.
  "In him [Garry Cook] was distilled the very essence of the modern football executive – the Nike heritage, the mad expansionism, the sense that a major part of Manchester City's future lay in energy drink retail, and of course the laserlike focus on "the product" that resulted in him occasionally saying Manchester United when he meant Manchester City. He was the Premier League's most bungling Sith."