The antonyms for the word "most slumbersome" are energetic, lively, lively and active. Antonyms are words that have opposite meanings to a particular word. While "slumbersome" refers to being lethargic, sluggish, and slow, energetic represents a state of being full of drive, enthusiasm, and energy. Lively means being enthusiastic and full of energy. Active, on the other hand, represents a state of being busy and engaged in physical or mental activity. By knowing the antonyms for "most slumbersome," it is easier to communicate ideas more accurately and effectively, which helps to improve communication and comprehension.