Dictionary
Schwarz'schild ra"dius
Pronunciation: ( Ger. shvärts'shilt"; Eng. shwôrts'chīld", -shild), [key] Astron.
the radius at which a gravitationally collapsing celestial body becomes a black hole.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.