Dictionary
A•ge•na
Pronunciation: (u-jē'nu), [key]—
n. Rocketry.
a U.S. upper stage, with a restartable liquid-propellant engine, used with various booster stages to launch satellites into orbit around the earth and send probes to the moon and planets: also used as a docking target in the Gemini program.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.