interschool vs interscholastic

interschool and interscholastic both are adjectives.

Word	Noun	Adjective	Verb	Adverb
interschool	No	Yes	No	No
interscholastic	No	Yes	No	No

As adjectives, interschool and interscholastic are synonyms defined as:

interschool and interscholastic: used of competition or cooperation between secondary schools

interschool (adjective)	interscholastic (adjective)
used of competition or cooperation between secondary schools	used of competition or cooperation between secondary schools