Of or pertaining to those activities occurring within a single institution or organization, such as intramural sports involving students of a single school; an intramural debate within a professional society.

Activities between groups in a college or university. Usually athletics, but can mean any activity.

carried on within the bounds of an institution or community; "most of the students participated actively in the college's intramural sports program"

Being within the walls, as of a city.

Being within the substance of the walls of an organ; as, intramural pregnancy.

intra = within + murus = wall; within the wall of an organ.