Source : Webster's Revised Unabridged Dictionary (1913)

Next \Next\ (n[e^]kst), a., superl. of {Nigh}. [AS. n[=e]hst,
   ni['e]hst, n[=y]hst, superl. of ne['a]h nigh. See {Nigh}.]
   1. Nearest in place; having no similar object intervening.
      --Chaucer.

            Her princely guest Was next her side; in order sat
            the rest.                             --Dryden.

            Fear followed me so hard, that I fled the next way.
                                                  --Bunyan.

   2. Nearest in time; as, the next day or hour.

   3. Adjoining in a series; immediately preceding or following
      in order.

            None could tell whose turn should be the next.
                                                  --Gay.

   4. Nearest in degree, quality, rank, right, or relation; as,
      the next heir was an infant.

            The man is near of kin unto us, one of our next
            kinsmen.                              --Ruth ii. 20.

   Note: Next is usually followed by to before an object, but to
         is sometimes omitted. In such cases next in considered
         by many grammarians as a preposition.

   {Next friend} (Law), one who represents an infant, a married
      woman, or any person who can not appear sui juris, in a
      suit at law.

Source : WordNet®

next friend
     n : (law) a person who acts on behalf of an infant or disabled
         person