betrothal

from WordNet (r) 3.0 (2006)

betrothal
    n 1: a mutual promise to marry [syn: {betrothal}, {troth},
         {engagement}]
    2: the act of becoming betrothed or engaged [syn: {betrothal},
       {espousal}]

from The Collaborative International Dictionary of English v.0.48

Betrothal \Be*troth"al\, n.
   The act of betrothing, or the fact of being betrothed; a
   mutual promise, engagement, or contract for a future marriage
   between the persons betrothed; betrothment; affiance. "The
   feast of betrothal." --Longfellow.
   [1913 Webster]