IPA: /ˌɪntrəˈmjʊrəl/
KK: /ɪntrəˈmʊrəl/
Relating to activities or events that take place within a specific institution, especially a school or college, often involving competition among its members.
The school organized intramural sports to encourage students to participate in physical activities.
Intramural is formed from "intra-" (meaning within) and "murus" (meaning wall in Latin). The word refers to activities or events that take place within the walls of an institution, such as a school or college.
Think of activities happening 'within' ('intra-') the 'walls' ('murus') of a school or college — that's what intramural means.