The word "most bushy tailed" has a positive connotation, typically used to describe someone who is energetic, enthusiastic or alert. The antonyms for this phrase, on the other hand, would have a negative connotation. These words would describe someone who is unenergetic, tired, sluggish or apathetic. Some examples of antonyms for "most bushy tailed" could include lethargic, sleepy, sluggish, disinterested or indifferent. The use of antonyms can help to provide a more robust description of someone's behavior or personality, and can help to highlight the specific qualities that make them unique.