The term "brass bound" typically refers to something that is sturdy, unyielding, and rigid. Antonyms for this phrase would therefore describe something that is flexible, adaptable, and pliable. Words like "malleable," "pliant," "bendable," and "yielding" could all be seen as antonyms for "more brass bound." Similarly, words like "fluid," "changeable," "variable," and "unpredictable" would suggest a lack of rigidity and steadfastness. Antonyms for "brass bound" might be used to describe a person's approach to a problem, a company's management style, or even the weather on a given day.