Source : Webster's Revised Unabridged Dictionary (1913)

Inside \In"side`\, a.
   1. Being within; included or inclosed in anything; contained;
      interior; internal; as, the inside passengers of a
      stagecoach; inside decoration.

            Kissing with inside lip.              --Shak.

   2. Adapted to the interior.

   {Inside callipers} (Mech.), callipers for measuring the
      diameters of holes, etc.

   {Inside finish} (Arch.), a general term for the final work in
      any building necessary for its completion, but other than
      unusual decoration; thus, in joiner work, the doors and
      windows, inside shutters, door and window trimmings,
      paneled jams, baseboards, and sometimes flooring and
      stairs; in plaster work, the finishing coat, the cornices,
      centerpieces, etc.,; in painting, all simple painting of
      woodwork and plastering.

   {Inside track}, the inner part of a race course; hence,
      colloquially, advantage of place, facilities, etc., in
      competition.

Source : WordNet®

inside track
     n 1: a favorable position in a competition; "the boss's son had
          the inside track for that job"
     2: the inner side of a curved racecourse