definition of stool
The definition of a stool is a seat without arms supported by three or four legs. An example of a stool is a seat that you'd sit on at a bar. Stool is the waste matter in a bowel movement. An example of stool is the source of the sample provided to a medical lab to check for stomach parasites. a piece of furniture for one person to sit on, typically having a round seat, three or four legs or a central post, and no back or arms.