The antonyms for the word "unnotable" are remarkable, notable, significant, extraordinary, impressive, memorable, exceptional, and outstanding. These words are used to describe someone or something that stands out or is worthy of attention. Remarkable implies that something is worthy of remark or comment. Notable suggests that someone or something is worthy of notice or attention. Significant describes something that has meaning or importance. Extraordinary implies that someone or something is beyond ordinary or common. Impressive suggests that something evokes admiration or awe. Memorable describes something that is likely to be remembered. Exceptional and outstanding imply that someone or something is superior or highly accomplished.