n.1.  A narrow opening; a groove or slit: a slot for coins in a vending machine; a mail slot.
2.  A gap between a main and auxiliary airfoil to provide space for airflow and facilitate the smooth passage of air over the wing.
3. a.  An assigned place in a sequence or schedule: a new time slot for a TV program.
b.  A position of employment in an organization or hierarchy.
 4.  Computers   An expansion slot.
5.  Informal   A slot machine designed for gambling: lost $100 playing the slots.
6. a.  Football   A space or gap between an end and a tackle in an offensive line.
b.  Sports   An unmarked area in front of the goal between the face-off circles on an ice hockey rink.