apogee

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

• noun Astronomy The point in an orbit around the planet Earth where the orbiting body is farthest from the planet.
• noun The analogous point in an orbit around a celestial body other than Earth. Not in technical use.
• noun The farthest or highest point; the apex.

from The Century Dictionary.

• noun That point in the orbit of a planet or other heavenly body which is at the greatest distance from the earth; especially, that particular point of the moon's orbit.
• noun Figuratively, the highest or most distant point; climax; culmination.

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

• noun (Astron.) That point in the orbit of the moon which is at the greatest distance from the earth.
• noun Fig.: The farthest or highest point; culmination.

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

• noun astronomy The point, in an orbit about the Earth, that is furthest from the Earth: the apoapsis of an Earth orbiter.
• noun astronomy, more generally The point, in an orbit about any planet, that is farthest from the planet: the apoapsis of any satellite.
• noun The point, in any trajectory of an object in space, where it is furthest from the Earth.
• noun figuratively The highest point.

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

• noun a final climactic stage
• noun apoapsis in Earth orbit; the point in its orbit where a satellite is at the greatest distance from the Earth