The antonyms for the word "un-meticulous" are meticulous, careful, attentive, exact, thorough, precise, accurate, exacting, diligent, and scrupulous. These words describe someone who pays attention to detail, takes care to do things properly, and is conscientious in their work. Someone who is un-meticulous, on the other hand, is careless, sloppy, haphazard, negligent, slapdash, and lackadaisical. These are traits that are not desirable in most situations, especially in professional or academic settings where precision and accuracy are required. It is important to strive for meticulousness in whatever task one is engaged in to achieve the desired outcome.