What Classroom Thesaurus is
At the centre is a small, plain idea: a word can mean more than one thing, and its synonyms and antonyms belong to whichever meaning they are the synonym or antonym of. Classroom Thesaurus keeps that structure instead of flattening it away. Look up a word and you see each of its distinct senses as its own group, each with a short plain-language gloss and the synonyms and antonyms that go with that sense -- not with the word in general.
The lookup surface sits on top of the platform’s shared study-set engine. Each word’s synonyms become study cards a student can practice with the same six modes the rest of the platform uses -- flashcard flip, match, test, and the rest -- with the same deterministic SM-2 spaced repetition scheduling review. Antonyms are shown for reference; they are not drilled as if they were synonyms, because "opposite of" and "synonym of" are different skills and mixing them would silently mislabel a practice card.
Honestly, where the build is: the thesaurus, the sense grouping, and the synonym practice mode are built and tested as a standalone classroom surface, not yet wired into the editor or the rest of the writing tools. A standalone public lookup page at this address is early access and is being opened up gradually. Where something is a plan rather than an open door, this page says so.