Innate, inborn.
Born or originating in, native to a land or region, especially before an intrusion.
In particular, of or relating to a people (or their language or culture) that inhabited a region prior to the arrival of people of other cultures which became dominant (e.g., through colonialism), and which maintains a distinct culture.
Within the substance of the walls of an organ.
Within the walls; within one institution, particularly a school.
A (usually sports) competition between teams belonging to the same school.