Definitions of stool:

noun: a simple seat without a back or arms
noun: (forestry) the stump of a tree that has been felled or headed for the production of saplings
noun: solid excretory product evacuated from the bowels
noun: a plumbing fixture for defecation and urination
verb: react to a decoy, of wildfowl
verb: lure with a stool, as of wild fowl
verb: have a bowel movement
verb: grow shoots in the form of stools or tillers