tripod

n. [ L. tripus, -odis, Gr. &unr_;; &unr_; (see Tri-) + &unr_;, &unr_;, foot. See Foot, and cf. Tripos, Trivet. ] 1. Any utensil or vessel, as a stool, table, altar, caldron, etc., supported on three feet. [ 1913 Webster ]

☞ On such, a stool, in the temple of Apollo at Delphi, the Pythian priestess sat while giving responses to those consulting the Delphic oracle. [ 1913 Webster ]

2. A three-legged frame or stand, usually jointed at top, for supporting a theodolite, compass, telescope, camera, or other instrument. [ 1913 Webster ]

Tripod of life, or
Vital tripod (Physiol.), the three organs, the heart, lungs, and brain; -- so called because their united action is necessary to the maintenance of life. [ 1913 Webster ]