The term "Beau Brummell" is often used to describe a man who is stylish, fashionable, and impeccably groomed. However, there are a few antonyms for this phrase that describe the opposite of this ideal. For example, a man who is disheveled, unkempt, or messy might be described as a "slob" or "slovenly." Similarly, a man who is unfashionable, outdated, or out of touch with current trends might be called "unstylish" or "old-fashioned." Finally, a man who is careless, sloppy, or careless with his appearance might be described as "careless" or "slipshod.