The term "juiced up" is often used to describe someone who is filled with energy or excitement. However, there are several antonyms for this term that describe a lack of energy or enthusiasm. These include words like sluggish, lethargic, apathetic, unenthusiastic, and dispirited. "Sluggish" refers to a slow-moving or lethargic state, while "lethargic" implies a lack of energy or enthusiasm. "Apathetic" suggests a lack of interest or concern, while "unenthusiastic" implies a lack of excitement or passion. "Dispirited" refers to a feeling of dejection or discouragement, which is the opposite of being "juiced up.