Source : Webster's Revised Unabridged Dictionary (1913)

Affiance \Af*fi"ance\, v. t. [imp. ? p. p. {Affianced}; p. pr. ?
   vb. n. {Affiancing}.] [Cf. OF. afiancier, fr. afiance.]
   1. To betroth; to pledge one's faith to for marriage, or
      solemnly promise (one's self or another) in marriage.

            To me, sad maid, he was affianced.    --Spenser.

   2. To assure by promise. [Obs.] --Pope.