The word "most duplicating" has several antonyms that are known to be the opposite of its meaning. The first antonym is "unique," indicating that something is one-of-a-kind and original, rather than copied or reproduced. Another antonym is "varied," implying that something differs in appearance, character, or type, rather than being the same or duplicating. The third antonym is "singular," suggesting that something is one or only one in number, rather than being in multiple copies. Lastly, "distinct" is another antonym that means something is unique or different from other things, rather than being identical or duplicating. Therefore, these antonyms provide alternative words to describe something that is not "most duplicating.