The phrase "being up and about" refers to being active and moving around, but its antonyms describe the opposite. "Inactive" means not engaging in physical or mental activity, while "sedentary" describes a lifestyle that involves sitting or lying down for extended periods. "Immobile" suggests an inability to move or travel, while "idle" suggests a lack of purpose or ambition. "Sluggish" implies a slow or lethargic pace, and "lethargic" describes a state of tiredness or apathy that discourages activity. Overall, the antonyms of "up and about" emphasize stillness, inactivity, and a lack of energy or motivation.