stadium

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A large, usually open structure for sports events with tiered seating for spectators.
• noun A course on which foot races were held in ancient Greece, usually semicircular and having tiers of seats for spectators.
• noun An ancient Greek measure of distance, based on the length of such a course and equal to about 185 meters (607 feet).
• noun Medicine A stage or period in the course of a disease.
• noun Biology A stage in the development or life history of an organism.

from The Century Dictionary.

• noun In zoology, same as stage, 9.
• noun In entomology, same as instar.
• noun A Greek itinerary unit, originally the distance between successive stations of the shouters and runners employed to estimate distances.
• noun Hence A Greek course for foot-racos, disposed on a level, with sloping banks or tiers of seats for spectators rising along its two sides and at one end, which was typically of semicircular plan.
• noun A stage; period; in medicine, a stage or period of a disease, especially of an intermittent disease.

from the GNU version of the Collaborative International Dictionary of English.

• noun A Greek measure of length, being the chief one used for itinerary distances, also adopted by the Romans for nautical and astronomical measurements. It was equal to 600 Greek or 625 Roman feet, or 125 Roman paces, or to 606 feet 9 inches English. This was also called the Olympic stadium, as being the exact length of the foot-race course at Olympia.
• noun A race course; especially, the Olympic course for foot races.
• noun A modern structure, with its inclosure, resembling the ancient stadium{2}, used for athletic games which are typically played out-of-doors; such stadiums are usually large structures without roofs, though some modern stadiums may have a protective dome overhead. It may be contrasted with the arena, the term commonly used for smaller structures at which indoor games are played.
• noun A kind of telemeter for measuring the distance of an object of known dimensions, by observing the angle it subtends; especially (Surveying), a graduated rod used to measure the distance of the place where it stands from an instrument having a telescope, by observing the number of the graduations of the rod that are seen between certain parallel wires (stadia wires) in the field of view of the telescope; -- also called stadia, and stadia rod.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A venue where sporting events are held.
• noun An ancient Greek race course, especially, the Olympic course for foot races.
• noun now historical A Greek measure of length, being the chief one used for itinerary distances, also adopted by the Romans for nautical and astronomical measurements, equal to 600 Greek or 625 Roman feet, or 125 Roman paces, or to 606 feet, 9 inches.
• noun A kind of telemeter for measuring the distance of an object of known dimensions, by observing the angle it subtends.
• noun In surveying, a graduated rod used to measure the distance of the place where it stands from an instrument having a telescope, by observing the number of the graduations of the rod that are seen between certain parallel wires (stadia wires) in the field of view of the telescope.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a large structure for open-air sports or entertainments