To be recumbent means to be lying down or resting in a horizontal position. Antonyms for this term include standing, sitting, upright, vertical, and erect. Being upright refers to being in an erect position with the body held straight up and down, while sitting means being in a seated position where the body rests on a chair or other surface. Vertical refers to a position perpendicular to the ground, while erect denotes standing tall with the body held straight. These antonyms highlight the opposite of being recumbent, which is an inactive or resting state. By being in an upright or vertical position, it is evident that the body is active and alert.