The word "most highfaluting" is an informal term that means pretentious or pompous. Its antonyms could include words such as humble, simple, unassuming, and modest. These antonyms represent qualities that are contrary to the notion of ostentatiousness, such as being down-to-earth, straightforward, or sincere. Other antonyms for "most highfaluting" might include words such as informal, unpretentious, casual, and relaxed. These qualities are often associated with conversations or situations that eschew formality or showiness in favor of a more laid-back or natural approach. Ultimately, antonyms for "most highfaluting" are words that express the opposite sentiment, one of simplicity, and honesty.