The Collaborative International Dictionary of English v.0.48:
Footstool \Foot"stool`\, n. A low stool to support the feet of one when sitting. [1913 Webster]WordNet (r) 3.0 (2006):
footstool n 1: a low seat or a stool to rest the feet of a seated person [syn: footstool, footrest, ottoman, tuffet]