'Libration point' definitions:

Definition of 'Libration point'

From: GCIDE
  • Libration point \Li*bra"tion point`\ (l[-i]*br[=a]"sh[u^]n point`), n. any one of five points in the plane of a system of two large astronomical bodies orbiting each other, as the Earth-moon system, where the gravitational pull of the two bodies on an object are approximately equal, and in opposite directions. A solid object moving in the same velocity and direction as such a libration point will remain in gravitational equilibrium with the two bodies of the system and not fall toward either body. [1913 Webster]