The antonyms for the word "un-meaning" include significant, purposeful, meaningful, important, and significant. These antonyms refer to something that has a definite sense or purpose, and is not vague, meaningless, or empty. Something that is significant is notable, noteworthy, or valuable. Purposeful refers to something that has been planned or deliberate, whereas meaningful refers to something that is full of meaning, importance, or significance. In contrast, something that is un-meaning lacks any sense or purpose, and cannot hold any real value. By using antonyms of un-meaning, one can communicate more effectively and convey a sense of importance, purpose, and value to their writing or speech.