1. The physical makeup of a body, including the mode of performance of its functions, the activity of its metabolic processes, the manner and degree of its reactions to stimuli, and its power of resistance to the attack of pathogenic organisms.
2. In chemistry, the number and kind of atoms in the molecule and the relation they bear to each other.
Origin: L. Constitutio, constitution, disposition, fr. Constituo, pp. -stitutus, to establish, fr. Statuo, to set up