IPA: /ˌɪn.təˈskɒl.ə.stɪk/
KK: /ɪnˌtɜrskəˈlæstɪk/
Relating to activities or events that take place between different schools.
The interscholastic competition brought together teams from various high schools.
Interscholastic → It is formed from "inter-" (meaning between) and "scholasticus" (from Latin, meaning of schools or pertaining to schools). The word "interscholastic" refers to activities or competitions that occur between different schools.
Think of activities that happen 'between' ('inter-') different 'schools' ('scholasticus') — that's what interscholastic means.