Pronunciation: (kas'u-grān"), [key] Astron.
a reflecting telescope in which the light, passing through a central opening in the primary mirror, is brought into focus a short distance behind it by a secondary mirror. Also called Cas•se•grain'i•an tel'escope Pronunciation: (kas"u-grā'nē-un). [key]
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.