The term "most catechistic" refers to something that is highly instructional, educational, or pedantic in nature. Antonyms for this word can be a range of terms, including enigmatic, mysterious, obscure, vague, or ambiguous. These words refer to things that are complex and difficult to understand, rather than informative or didactic. Another antonym for "most catechistic" is the word "vague," which refers to something that is not clearly defined, articulated, or specified. Similarly, the term "non-instructive" can also be used as an antonym for "most catechistic," implying that something is lacking in educational or instructional value.