Source : Webster's Revised Unabridged Dictionary (1913)

Most \Most\, adv.

   {Most-favored-nation clause} (Diplomacy), a clause, often
      inserted in treaties, by which each of the contracting
      nations binds itself to grant to the other in certain
      stipulated matters the same terms as are then, or may be
      thereafter, granted to the nation which receives from it
      the most favorable terms in respect of those matters.

            There was a ``most-favored-nation'' clause with
            provisions for the good treatment of strangers
            entering the Republic.                --James Bryce.

            Steam navigation was secured by the Japanese as far
            as Chungking, and under the most-favored-nation
            clause the right accrued to us.       --A. R.
                                                  Colquhoun.
Mother's Day \Moth"er's Day\
   A day appointed for the honor and uplift of motherhood by the
   loving remembrance of each person of his mother through the
   performance of some act of kindness, visit, tribute, or
   letter. The founder of the day is Anna Jarvis, of
   Philadelphia, who designated the second Sunday in May, or for
   schools the second Friday, as the time, and a white carnation
   as the badge.

Source : WordNet®

Mother's Day
     n : second Sunday in May