There is a micro-phenomenon of new wave, special snowflake directors that try to revolution the canons of classical opera. I saw Carmen being banged behind a burning car next to what looked like a flamenco-infused Thunderdome. That was in Paris opera, stronghold of modernist SJW nonsense.
Here, the expression is a shorter version of matriculation college. In a number of Canadian cities, many government-run secondary schools are called collegiates or collegiate institutes (C.I.), a complicated form of the word college which avoids the usual post-secondary connotation.
The thesaurus of synonyms and related words is fully integrated into the dictionary. Click on the thesaurus category heading under the button in an entry to see the synonyms and related words for that meaning. Words used to describe schools and colleges:coed, collegiate, fee-paying... This is the British English definition of coed.