inside

The interior or inner part.

The left-hand side of a road if one drives on the left, or right-hand side if one drives on the right.

The side of a curved road, racetrack etc. that has the shorter arc length; the side of a racetrack nearer the interior of the course or some other point of reference.

(colloquial) (in the plural) The interior organs of the body, especially the guts.

(dated, UK, colloquial) A passenger within a coach or carriage, as distinguished from one upon the outside.

(slang) The inside scoop; information known only to certain involved people.