Source : Webster's Revised Unabridged Dictionary (1913)

   {On one's honor}, on the pledge of one's honor; as, the
      members of the House of Lords in Great Britain, are not
      under oath, but give their statements or verdicts on their
      honor.

   {Point of honor}, a scruple or nice distinction in matters
      affecting one's honor; as, he raised a point of honor.

   {To do the honors}, to bestow honor, as on a guest; to act as
      host or hostess at an entertainment. ``To do the honors
      and to give the word.'' --Pope.

   {To do one honor}, to confer distinction upon one.

   {To have the honor}, to have the privilege or distinction.

   {Word of honor}, an engagement confirmed by a pledge of
      honor.

Source : WordNet®

point of honor
     n : a concern that seriously reflects on your honor