The Collaborative International Dictionary of English v.0.48:

Trothplight \Troth"plight`\, v. t.
   To betroth. [Obs.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Trothplight \Troth"plight`\, a.
   Betrothed; espoused; affianced. [Obs.] --Shak.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Trothplight \Troth"plight`\, n.
   The act of betrothing, or plighting faith; betrothing. [Obs.]
   --Shak.
   [1913 Webster]